Joint Japanese-European Mercury Probe Having Troubles

On October 20, 2018, the European Space Agency (ESA) in partnership with the Japanese Aerospace Exploration Agency (JAXA) launched probe to investigate planet Mercury, the innermost planet of the solar system with several flybys culminating with going into orbit around the little planet for longer observations. The probe, called BepiColombo, launched atop an Ariane 5, now retired. 

It was reported today that the probe's thrusters have malfunctioned and the agencies aren't yet sure if it will be able to achieve orbit. 

The BepiColombo spacecraft ... could be feeling the heat even before it reaches its destination: Mercury. Thanks to a glitch, the spacecraft's thrusters are no longer operating at full power. The team has yet to determine how this will impact upcoming maneuvers, like a Mercury flyby set for later this year.

Destined to become just the second mission to orbit Mercury when in December 2025, BepiColombo is composed of two probes and something called the "Mercury Transfer Module" that scientists hope will answer many perplexing questions about the smallest planet in our solar system. (To be clear, BepiColombo has performed Mercury flybys before, but is yet to actually enter Mercury's orbit.)

The Mercury Transfer Module is intended to address questions like how a planet as blisteringly hot as Mercury could have ice in its polar craters. It implies the conduction of heat in the planet's surface is so low that thermal equilibrium favors heat radiating away from the planet over being conducted to the poles. Among other questions. 

The 48-million-mile-long (77-million-kilometer-long) journey to Mercury is far from straightforward for BepiColombo; the spacecraft will make a total of nine planetary flybys before being inserted into the relatively tiny planet's orbit. And, as ESA reports, the glitch experienced by the spacecraft on April 26 has complicated this journey further.

BepiColombo experienced the glitch as it was preparing for a maneuver to set it up for its fourth flyby of Mercury on Sept. 5, 2024. The problem centers on the Mercury Transfer Module, the leftmost module in this diagram.

The Mercury Transfer Module is equipped with solar arrays and an electric propulsion system used to generate thrust. As the spacecraft was about to begin its April 26 maneuver, however, operators found that the Transfer Module had failed to deliver enough electrical power to its thrusters.

As soon as the fault was identified, ESA operators set about rectifying it. By May 7, the team had restored power to the thrusters such that they reached 90% full capacity, but the power available from the Mercury Transfer Module is still below what it should be. This means BepiColombo is continuing to operate without its full thrust.

The ESA hasn't yet determined if the thrusters can still perform the job they're required to do, saying the BepiColombo team's main priorities are to keep the spacecraft's thrust stable at its current sub-optimal levels, and to work out how the spacecraft will handle upcoming maneuvers at less than full propulsion. The mission is scheduled to continue through 2028, or 10 years in space, with flybys set for Sept. 5 this year, with a fifth and sixth flyby set for Dec. 2, 2024, and Jan. 9, 2025. After that final flyby is when the spacecraft is to go into orbit around Mercury. If the thrusters can do that.

Intuitive Machines Improving Their Next Lunar Lander

The Intuitive Machines lander IM-1, Odysseus - quickly renamed Odie -  got a lot of attention and coverage here on the blog. It was, after all, the first US launched vehicle to land on the moon since the end of the Apollo program when it landed on February 22nd. Adding to the story was that the mission was seriously barfed up on the way to the moon but fixed in a story that would make TV's McGyver proud. Yes, the word "landing" only applied in the loosest sense of the word and the mission was a continuous string of "making do with what we got", but Intuitive Machines reported every paying customer was happy with their results. 

Facing that story, though, the company has started work on improvements to the next lander that will improve its chances of getting more right by the mission plans. IM-2 is set to be launched "later in the year."

In a May 14 earnings call, Steve Altemus, chief executive of Intuitive Machines, said the company will upgrade communications, tracking and landing systems based on the lessons from the company’s IM-1 mission in February, which landed but tipped over nearly on its side.

Those upgrades are based on an internal review of the performance of the IM-1 mission. “The review resulted in software and hardware advancements that we believe expand our technical capability to track our vehicle accurately in space and land with 20 times better precision on our next mission,” he said.

Other changes will include changing the placement of antennas on the lander to improve bandwidth and provide lower Bit Error Rate communications.

“The technical improvements for IM-2 are vertically integrated capabilities within the company that we can perform with little or no impact on our intended quarter 4 2024 launch date or require any additional capital investment while we continue assembly of the flight vehicle.”

There was also mention of “more robust test and verification processes” for IM-2. You might recall the story that during the final checkout before liftoff, the crew at the launch pad failed to disable a safety switch on a laser rangefinder on the lander before launch, and the followup verification procedures (most likely visual inspections) didn't identify that problem. That kept the laser from being used as intended during landing. Company executives said shortly after the landing that had the rangefinders been working, they believe they would have had a fully successful landing.

The company is also working on longer term missions, including an IM-3 lander scheduled for 2025 which will be anchored by NASA's Commercial Lunar Payload Services (CLPS) contract payloads, and a totally private sector mission after that. As well as others farther into the future.

In this screen capture from this video, you can see the leg on the left is broken and doesn't look like the one on the right.  In this photo, the engine is still firing and keeping Odie vertical.  Moments after the engine was cut, it tipped over, taking about two seconds to come to rest. 

SpaceNews spends some time and column space on Intuitive Machines' business picture and it certainly looks like their work on Odie was well received. The call they mention (quoted above) was a May 14, end of the quarter earnings call. They don't say if the company considers this their first quarter of the year (calendar year) or the second (fiscal year matching the Fed.gov fiscal year).

The company reported $73.1 million of revenue in the quarter, far higher than the $18.2 million in the same quarter a year ago. The majority of that revenue, more than $40 million, came from the company’s OMES III engineering services contract it has with NASA in the first full quarter of that contract, said Steve Vontur, acting chief financial officer.

Intuitive Machines had a net loss of $5.4 million in the quarter, an improvement on the $14 million loss in the first quarter of 2023. The company had a cash balance of $55.2 million as of the end of the quarter, which Vontur said would be sufficient for the company through the rest of the year. The company is forecasting revenues of between $200 million and $240 million for 2024.

Starliner Slips Another Four Days

The scheduled date for the Crewed Flight Test of Boeing's Starliner has slipped out again, due to Boeing troubleshooting a small helium leak in the Starliner spacecraft itself. The last date we had was this coming Friday, the 17th; that has now been rescheduled for Tuesday, May 21 at 4:43 pm EDT (2043 UTC).

Boeing's ground team traced the leak to a flange on a single reaction control system thruster on the spacecraft's service module.

There are 28 reaction control system thrusters—essentially small rocket engines—on the Starliner service module. In orbit, these thrusters are used for minor course corrections and pointing the spacecraft in the proper direction. The service module has two sets of more powerful engines for larger orbital adjustments and launch-abort maneuvers.

Like many other spacecraft, the thrusters are fueled by the toxic combination of hydrazine (N₂H₄) and nitrogen tetroxide (N₂O₄) using the helium just to pressurize the system. The leak is important because the Starliner is to stay docked at the ISS for the week of the CFT-1 mission and the pressure must be maintained. This is a common fuel/oxidizer system for small thrusters; the Crew Dragon currently docked to the ISS for the Crew 8 mission and the previous ones that have flown other missions have stayed docked for the months those missions stayed docked to the ISS.

According to NASA, engineers plan to address the helium leak using "spacecraft testing and operational solutions." In other words, managers don't anticipate any need to physically repair the leak.

The original cause of the launch scrub back on Monday, May 2nd, was due to a valve problem. ULA rolled the Atlas V back to their Vertical Integration Facility (VIF) to swap out the faulty pressure regulation valve on the Atlas V's Centaur upper stage. Once installed on the rocket, the new valve performed normally in tests inside the VIF. ULA will roll the rocket back to the launch pad before the next launch attempt; I think the last attempt at this mission rolled out two days before the launch date.

A view looking down onto the Starliner capsule atop its Atlas V launch vehicle inside the VIF at Cape Canaveral Space Force Station, Florida. Image credi: ULA

My first reaction to this picture was that I'd like to know what those two black streaks are, about 60 degrees apart on one side (top of the frame) and 120 degrees apart on the other side. They kinda look like burn marks. Then I thought maybe I don't really want to know that. "Ignorance is bliss" and all that.

Sierra's Dream Chaser On the way to KSC

It has been a while since we've heard anything about the acceptance and qualification testing of Sierra Space's Dream Chaser vehicle. That was in early February when Sierra Space did a public showing of the "mini space shuttle" at NASA's Neil Armstrong Test Facility in Sandusky, Ohio.

We learned today that testing has wrapped up in Ohio and the ship is bring moved to the Kennedy Space Center on Cape Canaveral where it will undergo its final tests before being mated to the Vulcan Centaur it's scheduled to ride to orbit. While no expected date is given, United Launch Alliance wants to get this launch accomplished before the end of '24 to complete certification of their Vulcan Centaur for DOD payloads. 

There has been speculation that Dream Chaser wouldn't be ready this year and that ULA has been considering either another payload or just lifting a dummy weight into orbit.

The first test saw the space plane, along with its additional cargo attachment ‘Shooting Star’, connected to the Vulcan Centaur stage separation mechanism for a shock test, followed by being placed on the most powerful spacecraft shaker table in the world. This testing took place over 5 weeks as teams replicated the conditions the space plane would see during launch on Vulcan. They also conducted the same testing but replicated the separation of the cargo attachment from Dream Chaser before de-orbiting.

After that round of testing, the space plane was moved into a thermal vacuum chamber which can cycle temperatures from -150F to +250F (-101C to +121C), the same temperatures it would see while in space.

Photo during testing on April 3 of the orbiter Tenacity and its cargo module Shooting Star inside the thermal vacuum testing chamber at NASA’s Armstrong Test Facility. Image from Sierra Space on X

Sierra also posted a video summarizing their time at the Armstrong Test Facility and their journey to this point. 

Happy Mother's Day

I bet I'm the last person to put up a mother's day post. Most of you will see this Monday - or late Sunday night at best.  

In this time of incessant attacks on the family structure; this time of abandoning the idea of motherhood and calling mothers "birthing persons," simple truths like this meme are a refreshing shelter. 

 I keep waiting for someone to try telling me "men can have babies, too" so I can say "name one."  "How did they do that?  Did they get a full uterus transplant?  Did they get ovary transplants, too, so it was their egg, or did they have an already fertilized egg implanted in their implanted uterus?"  Did they have birth canal created or transplanted in?  Sure wouldn't want to pass a baby through a penis.  It's a medical miracle.

Mother's Day and Father's Day both tend to be kind of low key around here as both of us lost our parents quite some time ago.  My mom passed around the first of December in 2013, so around 10-1/2 years ago and she was the most recent of the four.  My dad passed away in 1982, or 31 years before mom.  My mother-in-law was ahead of my mother, passing on in '99, while my father-in-law passed away after my father, but around 10 years ahead of his wife.    

All of my best to all you moms who drop by and read here.  If you still have your mom, I hope you at least called her.

 

 

Two Little, Unrelated Stories

First is the obvious one: the Planetary K-index remains at very high levels. See the plot just below. Note it has come down from its high of 9.0 in three different three hour periods in the last 24 hours (this plot is up to 0000 UTC on May 12 - or 8:00 PM EDT on the 11th). The bigger story is in those three letters in colored boxes at the upper right. That box was red and said G5 - major geomagnetic storm - last night but tonight indicates no storm is in progress. When you click on that green box, it opens a text window to say, "No G-Scale Geomagnetic Storming." This chart can be found here, and I look at it often.

An observation I've made many times is that when a high K-index starts to return to normal ranges, VHF propagation on the ham bands can get very, very good. That hasn't happened. The difference might be that my experience is K index dropping from much lower starting points, like K=4 down to K=3 or K=2, not the 8.33 down to 7.33 seen at the right edge of this bar graph. 

The predictions today have leaned toward the storm conditions continuing through the night in the US and possibly into Sunday night. The only way to reconcile that and the current "No G-Scale Geomagnetic Storming" is to say this might be "the calm before the (next) storm."  The NOAA site that predicts the extents of any aurora displays is looking just like last night.

All things considered, this was a pretty mild storm with only minor effects noted.  

According to NOAA, there have been some irregularities in power grid transmissions, and degraded satellite communications and GPS services. Users of SpaceX's Starlink satellite internet constellation have reported slower download speeds.

This is the most intense Solar storm recorded in more than two decades. The last G5 event—the most extreme category of such storms—occurred in October 2003 when there were electricity issues reported in Sweden and South Africa.

Two decades ago was cycle 23, and the intervening cycle 24 was the weakest cycle in 100 years. We got used to not having things like this happening; and nobody under 25 is likely to remember cycle 23 anyway, or any cycle before it.

You'll Never Guess What Boeing Proposed to Lower Mars Sample Return (MSR) Costs

Except you won't be surprised when I tell you their proposal was to "simplify the mission" by using the SLS. It reduces the mission to one flight of one (heavy lift) rocket, and you can argue that might be a good way to reduce risk. The problem is that SLS is the most expensive rocket flying in the world and NASA is trying to cut the cost of the MSR mission.

What's that saying about "when you only have a hammer every problem looks like a nail?" When you only have an SLS, everything looks like a mission for your SLS. 

Or something like that.

Planetary Geomagnetic Storm Has Hit

Borrowing wholesale from Spaceweather.com:  

EXTREME GEOMAGNETIC STORM--NOW! The biggest geomagnetic storm in almost 20 years is underway now. It has reached category G5--an extreme event. Sky watchers with dark skies may be able to see and photograph auroras even at low latitudes. Get away from city lights and look at the sky! Aurora alerts: SMS Text

CME STRIKE SPARKS WIDESPREAD AURORAS: The first of six CMEs hurled toward Earth by giant sunspot AR3664 hit our planet's magnetic field today. The impact on May 10th at 1645 UT jolted magnetometers around the world and sparked a geomagnetic storm, which is now extreme. More CMEs are following close behind and their arrival could extend the storm into the weekend. Sign up for Space Weather Alerts to receive instant text messages when the CMEs arrive.

If you're anywhere in the US north of the Gulf of Mexico, it's worth trying to get to a dark location a couple of hours after sunset to see if you can see auroras. They'll be pushing very far south. How far?  In most cases, the K-index has to get to 9 or higher to see them as far south as the Carolinas to Arkansas or so. 

HOWEVER, there's more to it. The first is that the value you see on charts like this are 3 hour averages. Geomagnetic storms also have gusts and peaks that can give shorter term visibility farther south. Next is the direction of Earth's magnetic field, denoted by Bz. South pointing geomagnetic fields produce auroras farther south, into the gulf coast, Texas and even Florida. This site has a plot of Bz, toward the top right of the page, the second row under a place for a video that's always there.  (Bz is currently staying pointing south).

This was the first hit of several CMEs that are coming and there are predictions later impacts will become the so-called cannibal CMEs, in which later, faster Coronal Mass Ejections catch up with and merge with earlier CMEs, giving them a bigger, higher impact. In this view you can see the monster-sized sunspot group 3664. It's the one that has thrown the group of CMEs in the Earth's direction.

Image from Spaceweather.com

As a sidenote, a ham radio group I read regularly had a plot from the same place that had 3664 next to what I think is Carrington's drawing of the spots that gave the famous, all-time world record CME named after him. The implication is that since the group is the same size, the CME could be as bad as the Carrington event. The size of the group is actually relatively low importance in this; what's more important is the magnetic configuration. For example, the caption to that sun picture says, "Giant sunspot AR3664 has a 'beta-gamma-delta' magnetic field that harbors energy for X-class solar flares." I've ranted before about how tired I am of continuous predictions that we're going to have another Carrington event. Something that has happened once in all of human history of observing the sky is suddenly supposed to happen routinely according to these folks. I know "doom sells" but it's kind of ridiculous out there. 

NASA Going With External Resources on Orion Heat Shield

Last week, I posted an introduction to the heat shield issues on the Orion capsule used during the Artemis I mission at the end of 2022 as I'm trying to gather as much info as I can. Today, Ars Technica's Stephen Clark posted a followup article on the topic, emphasizing that NASA has asked a panel of outside experts to review their investigation. 

As should be obvious, this is potentially a very serious issue. 

Since the Artemis I mission, engineers conducted sub-scale tests of the Orion heat shield in wind tunnels and high-temperature arcjet facilities. NASA has recreated the phenomenon observed on Artemis I in these ground tests, according to Rachel Kraft, an agency spokesperson.

One of the things that caught my eye was a statement by made by Victor Glover, pilot for the Artemis II mission, in a recent interview with Ars. “More than any picture or report, I've seen that heat shield, and that really set the bit for how interested I was in the details.” His summary of the analysis and testing so far was more pointed. “There's no guarantee that changing the trajectory is the answer.” That has been the standard answer so far. Change the trajectory to reduce the demands on the heat shield. 

"In late April, NASA chartered an independent review team which includes experts outside the agency to conduct an independent evaluation of the investigation results," Kraft said in a statement to Ars. "That review, scheduled to be complete this summer, ensures NASA properly understands this condition and has corrective actions in place for Artemis II and future missions."

For his part, Glover thinks they have a good team and they'll eventually find the answer. “We’ve got the right people. If there is a solution, we’ll figure it out.” 

But settling on a solution will only come after NASA determines what caused the Orion spacecraft's heat shield to perform the way it did. And there's no guarantee NASA will find a definitive root cause. While engineers have recreated the char loss on sections of Orion's heat shield in ground tests, they can't test the full 16.5-foot-diameter (5-meter) heat shield on the ground or replicate the exact material response or flight environment experienced on Artemis I.

"We have a lot of extrapolation for scale that we have to do," said Jeremy Vander Kam, deputy manager for Orion's heat shield at NASA's Ames Research Center, shortly after the Artemis I mission in 2022. "Similarly, our test facilities can't reach the combination of heat flux, pressure, shear stresses, etc., that an actual reentering spacecraft does. We're always having to wait for the flight test to get the final certification that our system is good to go."

I know some of you have worked in fluid dynamics, which is what we're talking about here. The Artemis capsule reenters at 25,000 mph, turning the atmosphere into superheated plasma that makes those plasma photos from Starship look like someone was just shining a pink light on it. The interaction of that plasma with the heat shield is what they're trying to model and understand. This isn't laminar flow like a barely flowing river, this is more like full-tilt, raging whitewater. 

"This is a very, very complicated thing," Glover said. "The heat flow alone is really complicated to understand—the physical dynamic forces of all that wind and plasma swirling around. Imagine looking at a raging river, a whitewater river, and trying to analyze just one spot. What's happening at that spot? Recreate it. Draw it. It's really complicated."

The other issue is that the capsule for Artemis II is already built and undergoing tests at the KSC. To modify the heat shield now would require disassembling the Orion crew module from its European service module, and returning it to a place where that work could be done. That would delay the Artemis II launch, probably by a year or more beyond its current target schedule in September 2025. 

A view through the window of the Orion spacecraft during the Artemis I reentry. All those streaks in the bottom of half of the frame, white or yellowish to orange or peach-like are small pieces of material coming off the heat shield. Image Credit to NASA. I edited the photo slightly to enhance the contrast.

Again, the approach to reducing this problem being talked about is to modify the reentry. The problem there is that there are only a handful of possibilities and the whole approach is based on the thought that a different reentry reduces the stresses on the shield. But according to Glover, they saw chunks flying off the heat shield (their euphemism is "liberation") very early in the reentry when those stresses were lower. "If the damaging pieces start very early, there's no guarantee that changing the trajectory is the answer. It will change something, but it won't necessarily fix it. So we need to understand the root cause, if it's knowable."

While We Wait

It was another day that got away from me today. On top of that, there's very little of what I consider meaningful news today. 

To clear the desk a little, I missed a couple of pretty big things in last night's post about Starliner being scrubbed and delayed.  I'll list them here in no particular order:

• When I said the mission, "...has been rescheduled for this Friday at 6:16 PM EDT" that was a terrible misreading of the information. It's not this Friday, May 10; it's next Friday, May 17. The time, at least, is the right set of numbers but that doesn't mean anything if you're looking for it on the wrong day. 

From NextSpaceflight.com's list of all coming launches. 

• Next was talking about relays and not valves (as what was buzzing). While I'd swear someplace I was reading said it was a relay, I don't remember where that was. I have to assume it's my fault and I always take responsibility for my screw-ups. 
• Finally, I used the headlines that blamed the scrub on the Atlas V, but the issue was in the Centaur upper stage. 

The issue was with an oxygen relief valve on the rocket’s Centaur upper stage. “The team is just not comfortable with the signatures that they’re seeing, the response out of that valve, so out of an abundance of caution, we are not going to continue with our launch operations today,” said Dillon Rice, ULA launch commentator, on NASA TV.

Which actually is worse than if was the Atlas V.  As commenter Beans pointed out, " First launched (for Atlas V) in 2001 and they're having this issue?" It's part of the launch vehicle for sure, but the Centaur upper stage has been flying since the 1960s, not 2001. Yeah, it's likely they've modified the design in the 70 years the design has been around, but hardware isn't changed without reason in a certified system like that. 

Atlas V Booster Issue Delays Starliner CFT-1

The first Crewed Test Flight was scrubbed last night around two hours before the scheduled launch and has been rescheduled for this Friday at 6:16 PM EDT. 

... But mission teams called the attempt off about two hours before Monday's planned liftoff, after identifying a faulty "oxygen relief valve" on the upper stage of Starliner's rocket ride, a United Launch Alliance (ULA) Atlas V. The valve was "buzzing," opening and closing rapidly, during the launch countdown, forcing the delay, ULA officials said.

Admittedly, I didn't work with relays very much in my design years; they're just not used very often in the kind of work I did (radio frequency (RF) applications). The only times I've seen relays buzzing it was caused by the voltage driving the relay's coils being too low, which implies that the issue here isn't the relay but the circuit driving it - possibly including the wiring. 

Originally, everyone involved was saying they should be able to try to launch again tonight. That lasted until some time this morning when they gave the date of the next try as Friday evening. Since it's a fairly good rule of thumb that, "in Space 1.0 nothing happens quickly - and manned flight isn't even that fast" I'll just keep an eye on it. Should they need to roll the Atlas V and Starliner stack back to their assembly area, that probably adds a couple of days on to the delay.

The CFT-1 Starliner Capsule on top of its Atlas V ride at the SLC-41 launch pad. Image Credit: ULA on Flickr

Guess We Wait Another Day for Starliner

Word got out around 8:30 PM that the Crewed Flight Test of Boeing's Starliner has been scrubbed for at least 24 hours, apparently due to an out of bounds reading from the Atlas V booster.  The exact problem wasn't talked about while I was watching/listening to the video coverage on NASA Spaceflight.com.

As of now, 9 PM as I write, the scrub has been called a 24 hour scrub, but that can change as the fault is looked into in more detail. 

Payload has provided a good summary of the story behind Starliner and how it got to this point. A more pointed story comes form Eric Berger at Ars Technica, who says, “The surprise is not that Boeing lost commercial crew but that it finished at all.” 

From where we sit today, knowing the story along the way, it's easy to lose sight of important details. Ten years ago when the private crewed spacecraft contracts were first being debated and discussed, pretty much everyone thought Boeing would be the easy winner. 

Boeing was the easy favorite. The majority of engineers and other participants in the meeting argued that Boeing alone should win a contract worth billions of dollars to develop a crew capsule. Only toward the end did a few voices speak up in favor of a second contender, SpaceX. At the meeting's conclusion, NASA's chief of human spaceflight at the time, William Gerstenmaier, decided to hold off on making a final decision.

A few months later, NASA publicly announced its choice. Boeing would receive $4.2 billion to develop a "commercial crew" transportation system, and SpaceX would get $2.6 billion. It was not a total victory for Boeing, which had lobbied hard to win all of the funding. But the company still walked away with nearly two-thirds of the money and the widespread presumption that it would easily beat SpaceX to the space station.

In addition to that $4.2 billion fixed price contract that they blew through, they've spent more money out their own pockets - an additional loss of $1.5 billion. In addition to that $1.5 billion loss, there are costs from lost opportunities. Dragon first carried people to the space station nearly four years ago. In that span, the Crew Dragon vehicle has flown thirteen public and private missions to orbit. Because of this success, Dragon will end up flying 14 operational missions to the station for NASA, earning a tidy fee each time, compared to just six for Starliner. 

The problems Boeing had were all self-created, all a result of their corporate culture not knowing how to manage a fixed price contract, instead of the cost-plus contracts behind everything else the spacecraft division of Boeing worked on. There are stories of different software groups essentially refusing to work with each other, managers creating "milestones" on their schedule that would get a payday when NASA approved but that meant little or nothing. There are stories that some Boeing managers have said, "we're never doing that again" when questioned about fixed price contracts and others say they will. In a time when the private sector is practically bursting with small, hungry, hardworking companies, if Boeing can't figure out how to live with fixed price contracts, those small companies will eat their lunch. Or buy the space division from Boeing and put them out of the business.

Boeing’s CST-100 Starliner being installed on its Atlas 5 rocket last week. Credit: NASA/Kim Shiflett

NASA & SpaceX Moving Toward Refueling Demos

As SpaceX prepares for the coming Integrated Flight Test, IFT-4, they're still working toward their important role in the Artemis program, the version of Starship that will land on the moon, called the Human Landing System or HLS. While the target for orbital simulations is "next year", they've already begun some tests during IFT-3 to try to capture data on various aspects of the problem. 

NASA contracted first SpaceX and later Blue Origin to develop manned lunar landers. Both ships have been designed for refueling on orbit and the way Artemis has been created to establish a larger presence on the moon than the Apollo missions makes it essential they achieve refueling. 

Amit Kshatriya, who leads the "Moon to Mars" program within NASA's exploration division, outlined SpaceX's plan to do this in a meeting with a committee of the NASA Advisory Council on Friday. He said the Starship test program is gaining momentum, with the next test flight from SpaceX's Starbase launch site in South Texas expected by the end of May.

"Production is not the issue," Kshatriya said. "They're rolling cores out. The engines are flowing into the factory. That is not the issue. The issue is it is a significant development challenge to do what they’re trying to do ... We have to get on top of this propellant transfer problem. It is the right problem to try and solve. We're trying to build a blueprint for deep space exploration."

During IFT-3, it was said they were doing testing involving transferring liquid oxygen (LOX) inside the Starship; part of a demonstration funded by NASA. Kshatriya said that while engineers are still analyzing the results of the LOX transfer, the test on the March Starship flight "was successful by all accounts."

"That milestone is behind them," he said Friday. Now, SpaceX will move out with more Starship test flights. The next launch will try to check off a few more capabilities SpaceX didn't demonstrate on the March test flight.

SpaceX has released conceptual drawings that depict two Starships docked and connected belly to belly for refueling.  Image credit: SpaceX

Before Starship's first landing on the Moon with astronauts, NASA's $2.9 billion Human Landing System (HLS) contract with SpaceX includes ship-to-ship propellant transfer testing and an unpiloted landing of a full-scale Starship on the lunar surface.

But each Starship test flight builds on the prior mission. This means pretty much every Starship test flight over the next couple of years will have goals that feed into the first Artemis lunar landing. During these upcoming Starship test flights, engineers will measure the slosh of propellants inside the ship, along with tank pressures, and observe how the fluids respond to impulses from small thrusters. In microgravity, these small rocket jets provide "settling thrust" to guide the ship's liquid toward the outflow needed for refueling.

Engineers will also monitor the boil-off rates of the methane and liquid oxygen in space. Over time, cryogenic liquids transition to a gaseous state without insulation or other measures to prevent boil-off. SpaceX and NASA officials want to know how much of the propellant will be lost from boil-off to know how many refueling tankers they need to launch for a Starship lunar landing mission.

Refueling is something that everyone involved in long term planning about spaceflight and making the entire solar system more accessible has said is the big engineering problem that needs to be solved. NASA's Kshatriya is comfortable that SpaceX is making good progress with the engineering analysis. 

One of the reasons SpaceX is working hard to build a second launch pad in Boca Chica is to support multiple launches closely spaced in time. For the first full-scale refueling demonstration, still looking to be in '25, SpaceX has to launch two Starships within three or four weeks of one another. The first Starship will serve as the target vehicle in low-Earth orbit and will have an augmented power system with more battery capacity to survive in space long enough for the launch of the second Starship that will be the refueling tanker. In addition, both ships will also have thermal insulation and vacuum jacketing around their internal plumbing to limit boil-off. "Otherwise, the demo itself will not be achieved," Kshatriya said.

This is hard, but it's doable. Various engineering groups have been working on this big task in the background over the years. Computer models and flight data from numerous rockets show it is possible to control cryogenic boil-off, tank pressures, and propellant settling in space. It's just the big step, getting the cryogenic propellants from one spacecraft to another in orbit has never been attempted. 

"In my mind, all the technical issues associated with cryo transfer in space are solved," said George Sowers, former chief scientist at SpaceX rival United Launch Alliance and a longtime proponent of depoting propellants in space. "It’s just a matter of demonstrating it and fine-tuning the technology and the procedures. So, I think we’re on the cusp. I’m happy to see SpaceX taking the steps to make it work."

This chart from a NASA Artemis meeting outlines plans for SpaceX's ship-to-ship cryogenic transfer demonstration planned for 2025. Image credit NASA: Amit Kshatriya

My belief is that there will be lots of learning going on here, in the usual SpaceX mode of try - and if you fail, figure out what went wrong and fix it. Not by '25, but maybe by 2030 this will be as routine as a Falcon 9 booster landing - and you remember how insane that was thought to be just about a decade ago.

It's a Good Thing It's Star Wars Day

It's a good thing because otherwise, I've got pretty much nothing worth mentioning.

As some of the recent Star Wars movies are playing in the next room, a thought occurs to me that has infected the world before. The Evil guy in last movies was Kylo Ren and the existence of Kylo Ren implies the existence of a Kylo Stimpy. 

Image source: Imgflip

Small Space News Story Roundup 35

Well... You know...

Ariane 6 is on the Launch Pad

Over the course of April, the first Ariane 6 vehicle has been assembled on the launch pad in French Guiana. First, they raised the core of the first new version of the rocket on its launch pad, replacing a full-scale ground model used for testing last year. Then, on April 30, the ESA gave us this update.  

The first Ariane 6 rocket to take flight is being pieced together at Europe's spaceport in Kourou, French Guiana. The two solid rocket fuel P120C boosters have now been connected to the central core. For this, the core was raised with a lifting beam and the boosters were moved the last few centimeters into their final positions.

With that, the core is supported by the boosters and the teams on the ground could complete the mechanical and electrical connections, followed by a series of functional controls.

Ariane 6 in with the strap-on P120C boosters. Image credit: ESA/ArianeGroup/Arianespace/CNES

There's still much to be done before we can expect a launch, with fueling tests, and all of the things done to verify it has been assembled correctly and can launch. There's a projected first mission and launch window.

The small satellites that will ride the first Ariane 6 rocket into orbit are scheduled to arrive at the French Guiana launch site later this month. The satellites will be encapsulated inside the Ariane 6 payload fairing and then raised on top of the rocket ahead of the first launch attempt, which could happen in a window between June 15 and July 31.

Ariane 6 is capable of essentially the same payloads and orbits of the Falcon 9 but isn't reusable. The European Space Agency just had to hire SpaceX to launch a pair of their Galileo satellites, and have a second launch booked as well. All because the EU currently has no rockets that are flying and have paid SpaceX 180 million euros ($193 million) for the two Falcon 9 launches. The Falcon 9 booster was dumped earlier this week because the orbit required every bit of fuel a Falcon 9 can carry, and stories are that the next Galileo launch will sacrifice the booster as well. The last Falcon 9 to be dumped was 146 missions ago. 

The ESA needs to get Ariane 6 flightworthy.

China Launches Lunar Sample Return Mission

Eric Berger at Ars Technica puts it this way: 

NASA hasn’t landed on the Moon in decades—China just sent its third in six years

Stings a bit but it's the honest truth. 

On Friday the country launched its largest rocket, the Long March 5, carrying an orbiter, lander, ascent vehicle, and a return spacecraft. The combined mass of the Chang'e-6 spacecraft is about 8 metric tons, and it will attempt to return rocks and soil from the far side of the Moon—something scientists have never been able to study before in-depth.

One of the difficulties in a mission to the far side of the moon (note to Bill Nelson - NOT the DARK side) is that with no atmosphere, and especially without an ionosphere to provide a natural way to get radio signals around the moon, there's no radio contact with the lander. To address that, China launched the Queqiao-2 relay satellite in March, which will serve as a radio relay between the Moon and operators back in China.

The Chang'e-6 spacecraft is intended to return something like 2 kg (4.4 lbs) of rocks to Earth in about a month.  Such a small quantity makes it seem like it may be a "proof of concept" mission before they try to bring back lots more.

About Orion's Heatshield Issues

Thanks to a tip from SpaceNews.com, I learned that NASA's office of the Inspector General released a report on May 1 covering the aspects of the Artemis 1 mission that are behind the reschedule of Artemis 3 from the end of this year until NET September of '25. In particular, they cover the heat shield issues with photographs that I haven't seen yet. Seeing them shines a whole new light on the investigation. 

The report reviewed problems with the Orion spacecraft, as well as ground equipment and the Deep Space Network, from the uncrewed Artemis 1 mission launched in November 16, 2022. The entire report, 43 pages, is here at the OIG's site. It can be downloaded directly as a pdf. 

The problem that's discussed the most is the heat shield, as mentioned as recently as last Saturday. 

NASA disclosed months after the flight that more of the ablative heat shield material had been lost during reentry than expected, but added that it has not posed a safety risk to the spacecraft.
...
According to the OIG report, NASA found more than 100 locations on the heat shield where material “chipped away unexpectedly” during the Artemis 1 reentry. The report included images showing pockmarked portions of the heat shield that had not previously been released by the agency.

"More than 100 locations" isn't a safety risk? They include one photograph. 

To me, that looks terrible, but I'll be the first to admit that I'm radio designer, and know next to nothing about heat shields.

The heat shield material, known as Avcoat, “wore away differently than NASA engineers predicted, cracking and breaking off the spacecraft in fragments that created a trail of debris rather than melting away as designed,” the report stated. “The unexpected behavior of the Avcoat creates a risk that the heat shield may not sufficiently protect the capsule’s systems and crew from the extreme heat of reentry on future missions.”

NASA has yet to find a root cause for the behavior of the heat shield material. In a response accompanying the report, Cathy Koerner, NASA associate administrator of exploration systems development, stated that ground testing “successfully recreated char loss” and that that the material in those tests “has the same features as observed on the Artemis I heat shield.” But the OIG report noted that while NASA was able to recreate the char loss, “they could not reproduce the exact material response or flight environment experienced during Artemis I.”

NASA has yet to identify a root cause of the behavior seen on Artemis I, and they consider that the biggest risk for the next Artemis mission. Amit Kshatriya, deputy associate administrator for the Moon to Mars Program, said their emphasis was to understand the physics going on here. 

“We’re getting close to the final answer in terms of that cause,” he said, while others analyze potential changes in the reentry trajectory to alter the heat load on the capsule.

“When we stitch it all together, we either will have flight rationale or we won’t,” he concluded. He didn’t estimate when that would be done, although NASA’s response to the OIG report offered a planned completion date of June 30. 

In addition to this big problem, there was another one in the same heat shield area. Three of four separation bolts on the base of the heat shield, used to separate the service module before reentry, experienced “unexpected melting and erosion” that post-flight analysis blamed on a “thermal model discrepancy.”

The bottom right picture looks more like corrosion on top of the molten bolt than just being melted, perhaps corrosion from being in saltwater. The answer is they'll design that area differently for use after Artemis II, but for the next mission, they've made some minor design changes to the bolt and will add some more heat resistant stuff around the bolt.

NASA Looking for Funding to De-Orbit Space Station

On one hand, de-orbiting the ISS isn't going to be hard. Get everyone and everything that's valued in any way out of it and stop those periodic missions to lift its orbit. It'll come down eventually. As the song says, "what goes up, must come down."  

Oh, wait. You want a controlled de-orbiting? Not like the way China does these things, but controlled so we can have a pretty good chance of not killing people or breaking valuable things on the ground? Well, that's gonna cost you. 

A roundabout and satirical way of introducing the story that NASA Administrator Bill Nelson is lobbying congress for more money to de-orbit the ISS.  The real problem is that some congress critters with some common sense are trying cut spending and Nelson can't see a way to do all of what NASA wants with the spending caps he has been faced with. 

The caps, in place for the 2024 and 2025 fiscal years, limit non-defense discretionary spending and were part of a deal enacted nearly a year ago in the Fiscal Responsibility Act to raise the debt ceiling. “These two years, ’24 and ’25, NASA has been cut between the two years $4.7 billion from our original request,” he said. “That’s going to have an effect on some of the contracts at all NASA centers.”

NASA, in its fiscal year 2024 budget request, sought $27.185 billion for the agency and projected requesting $27.729 billion in 2025. NASA received $24.875 billion in the final 2024 appropriations bill enacted in March and is requesting $25.384 billion in 2025, a difference of nearly $4.7 billion from the original projections last year.

In particular, this circles around a project called the United States Deorbit Vehicle (USDV), a spacecraft NASA plans to develop to handle the final deorbiting of the International Space Station at the end of the station’s life. That's been talked about as being 2030. 

NASA had requested $180 million for USDV in its fiscal 2024 budget request and $109 million for it in the 2025 request. Nelson, though, told members NASA wanted to get full funding for the vehicle as part of a domestic emergency supplemental spending bill proposed by the White House last fall for disaster relief and other purposes, but yet to be considered by Congress.

First thought: Bill, don't let the SLS folks near this. You want $289 million over two years? I know that can't be anything but a study, so don't let the SLS team touch those studies. Their version of the USDV will cost billions more than they bid and left to themselves it wouldn't be ready until 30 years after the station comes down randomly on its own. 

Second thought: don't go with the argument that we need this to protect us from Putin. It's a pretty sad line that reeks of a lack of imagination.

“Why is it an emergency?” he said. “Because we don’t know what Vladimir Putin is going to do.”

He suggested Russia might terminate its role on the ISS early or decide not to participate in the controlled deorbiting of the station. “We don’t know what the president of Russia is going to do, and we could be in an emergency situation that we have to get this structure that is as big as a football stadium down, and down safely, in 2031.”

NASA Administrator Bill Nelson, April 30, in congressional meetings. Image Credit: NASA/Bill Ingalls

For those who don't know, Bill Nelson used to be our local US representative and lived somewhere not too far from here on "the Space Coast." The first place we ever saw him was in a church in the northern part of Melbourne. He's a schmoozer, a politician. Don't depend on him to make difficult decisions. He can, however, put together a team of bright, accomplished people and let them make the decisions he can't.