As a quick refresher, Bandwagon is a SpaceX rideshare platform different from their longer-established Transporter rideshare platform. Transporter has flown many times; Monday night's Bandwagon 3 mission tells us that's the third mission of the platform. The primary difference is the orbits available to the new platform are different. Bandwagon flies to orbits inaccessible to Transporter.
The Transporter platform provides launches to sun-synchronous orbits, which are polar orbits that go over the same places on Earth at the same time every day so that the angle of sun and lighting is the same every day - but not every customer wants to launch to an SSO. It should be mentioned that the term polar orbit doesn't require the satellite go precisely over the north and south poles; deviations to 20 or 30 degrees are acceptable. Enter bandwagon, which flies to the second most requested orbit, at inclinations of up to approximately 45 degrees and satellites at altitudes of 550 to 605 kilometers.
Bandwagon-3 carried only three payloads: the 425Sat-3 spacecraft for South Korea’s military, Tomorrow-S7 for
weather forecasting company Tomorrow.io and Phoenix, the first reentry
vehicle by ATMOS Space Cargo, a German startup. By comparison, Bandwagon-1
carried 11 satellites while Bandwagon-2 had 30 satellites.
You'll find reports elsewhere that the 425Sat-3 spacecraft is a Synthetic Aperture Radar imaging satellite. I'll skip over the second and go to the ATMOS payload, because I covered that mission back in February. Interestingly, I find the European Spaceflight news is reporting that even though they haven't processed all the flight data of their Phoenix reentry vehicle, they're tentatively declaring it has been successful. Bandwagon 3 was launched Monday night, April 21, at 8:48 PM EDT, making it Tuesday morning, Apr. 22, at 0048 UTC. Approximately two hours after liftoff, the capsule re-entered the atmosphere, and a splashdown was expected to occur 30 minutes later.
While the company stated that it had not yet completed an analysis of all the data it collected, it confirmed that it had successfully received data from four commercial payloads aboard the vehicle and that it had initial indications that the heat shield had been inflated successfully.
“All in all, I would say it was a very successful mission,” said ATMOS Space Cargo CEO Sebastian Klaus during a post-flight press conference.
The company had said they hoped to acquire data and imagery of the vehicle following re-entry from a small chase plane, but the splashdown point ended up being about 300 miles farther off the coast than initially anticipated.
While the inclusion of this phase of the mission hinted that the company anticipated the vehicle successfully re-entering Earth’s atmosphere, it’s not clear that it had any chance of achieving this milestone.
PHOENIX 1 was reliant on the Falcon 9 upper stage to place it on a re-entry trajectory into Earth’s atmosphere. While SpaceX had initially outlined a re-entry angle for the Bandwagon-3 mission that was within acceptable limits, a last-minute change resulted in a significantly steeper re-entry angle than anticipated. According to Klaus, this angle exceeded the design constraints of the vehicle’s heat shield, thereby reducing the likelihood of the prototype surviving re-entry. However, a successful re-entry of the vehicle was not one of the three objectives outlined by the company before the mission was launched.
"... a last minute change resulted in a significantly steeper re-entry angle than anticipated"? Doesn't that sound like something went wrong either with the Falcon 9's upper stage, the Bandwagon hardware or something? Apparently not.
A comment to that post on European Spaceflight says that "last minute" was actually "a few weeks ago", so more like last month, and the adjustment wasn't just 300 miles further off the initial landing spot; the splashdown moved from Reunion Island in the Indian Ocean to 1200 miles off the coast of Brazil in the Atlantic.
The three mission objectives for the PHOENIX 1 test were to collect in-flight data from the capsule and its sub-components while in orbit, gather scientific data from customer payloads operating in low Earth orbit, and record data on the deployment and stabilization of the inflatable heat shield during atmospheric re-entry. According to the company, the first two objectives were completed successfully, while the third has been tentatively deemed a success.
Credit: SpaceX / ATMOS Space Cargo / European Spaceflight
With a first mission under its belt, the company is now working toward testing an upgraded version of its capsule, called PHOENIX 2. The first test flight of this upgraded variant is expected to take place in 2026.
The upgrade to the capsule is to its propulsion system, which means it will no
longer be dependent on its launch vehicle’s upper stage to complete the
deorbit maneuver.
Yes, that remark about 'last minute change' threw me off too. Andrew's comment in the comment section at the link does provide better understanding, but seems contrary to Klaus' statement.
ReplyDeleteIt strikes me as peculiar to declare, for a recovery vehicle, that the actual reentry and capsule recovery were not important to this mission. Such is testing.
I have noted that the two most frequent responses after a mission are; ebullient joy (upon safe splashdown), or, We got all the data we wanted (upon loss of vehicle).
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I have a question. I know the answer, generally speaking, yet still I ask.
In this day of super computers and modeling, now with AI!, and a host of ground-based test equipment, is the physical launch still necessary for a test mission?
The environment upward and right out the top of the atmosphere and into near space is well known. What was unknown is now known in a thousand ways.
The rocket, vehicle and capsule, can be modeled like never before. This is for flight without humans. At what point does it become utterly redundant, therefore unnecessary.
(For my question, I ignore any regulatory requirement.)
This is one of those things that can go pages and not just paragraphs. The direct answer is fully dependent on your trust in modeling.
DeleteAll models are simplifications of reality - approximations. Some things are essentially impossible to model - I mean random assembly kinds of errors, like a bad weld. From another perspective, this thing they're trying to do has never been done before, so maybe there are things modeled incorrectly because tests of the models never adequately tested those things.
Then there's the inherent problem that the models are running partial differential equations and you get into the "sensitive dependence on initial conditions" that PDEs are famous for.
It comes down to if you're going to sit on a rocket and bet your life on it, (or invest your pile of money in it) how comfortable are you with models based on partial differential equations?
I get the impression that the losses of the last two Starship test flights come down to things working in the model but not in real life.
My disclaimer here is that I've never worked with professional level models of these things, and haven't worked with models in my field almost ten years now. That's electromagnetics and Maxwell's Equations (also PDEs) have been experimentally verified countless times. The software simulations never, ever matched the experimental results exactly - to the number of displayed decimal places. How closely they matched depends on exactly what you were modeling.
Rick, SiG pointed out that you can't model properly what you don't understand/account for. The last two Starship launches illustrated this to a T, since there was no way they could model the staging completely and something bit them in the butt - probably harmonic resonance or something bending that shouldn't have.
DeleteSpace is hard, or at the very least, darn difficult.
Rick, my guess is where a company or country can computer model with any degree of confidence they will and save the flight costs. That we still have flights shows modeling is not foolproof.
ReplyDeleteAtmos, the whole company, had funding of about $15 million (actually Euros and I could not find all of it so $15 million is an approximation). The Phoenix re entry vehicle weighs about 500 pounds. It is a tiny company with a tiny product. Looks like SpaceX ran the flight to accomodate long term customer South Korean department of Defense. Flight changes might have been to accomodate Korean DOD too. Spacex could have given Atmos the flight for free and had no loss.
While the articles cite low participation quantities for bandagon flight they do not mention mass or volume quantities, space available, for the flight. This data may be available, I did not dig for more than 10 minutes. I can understand SpaceX launching to accomodate the needs of a good customer. I am curious if there are projects, sitting on shelf somewhere, that could be put on the flights at a discount (or free) and take a round about path to its orbit / objective. Like the Nancy Grace Roman telescope or maybe the Atmos Phoenix flight. Like an airline with empty seats, may as well fill them at any price.
Thanks, Jeff. Good content there.
DeleteAn earlier article on Atmos said their long term goal is to scale the vehicle up to carry 25 metric tons (55,000 pounds) per flight.
“Think about what you can do with 25 metric tons. You can talk about factories in space. You can talk about catching a complete satellite and bringing it back down to earth. You can think about bringing back a rocket upper stage and making rockets reusable"