That statement is hard to wrap your head around. With the 500th launch of a Falcon booster just last week, the concept of doing something new with a Falcon 9 is a bit hard to grasp. Haven't they done pretty much everything that can be done with a Falcon?
Not according to this week's Rocket Report from Ars Technica.
[T]he company tried something new following a launch on June 7 with a radio broadcasting satellite for SiriusXM. The Falcon 9's upper stage placed the SXM-10 satellite into an elongated, high-altitude transfer orbit, as is typical for payloads destined to operate in geosynchronous orbit more than 22,000 miles (nearly 36,000 kilometers) over the equator. When a rocket releases a satellite in this type of high-energy orbit, the upper stage has usually burned almost all of its propellant, leaving little fuel to steer itself back into Earth's atmosphere for a destructive reentry. This means these upper stages often remain in space for decades, becoming a piece of space junk that transits across the orbits of many other satellites.
Now, a solution ... SpaceX usually deorbits rockets after they deploy payloads like Starlink satellites into low-Earth orbit, but deorbiting a rocket from a much higher geosynchronous transfer orbit is a different matter. "Last week, SpaceX successfully completed a controlled deorbit of the SiriusXM-10 upper stage after GTO payload deployment," wrote Jon Edwards, SpaceX's vice president of Falcon and Dragon programs. "While we routinely do controlled deorbits for LEO stages (e.g., Starlink), deorbiting from GTO is extremely difficult due to the high energy needed to alter the orbit, making this a rare and remarkable first for us. This was only made possible due to the hard work and brilliance of the Falcon GNC (guidance, navigation, and control) team and exemplifies SpaceX's commitment to leading in both space exploration and public safety."
This graphic illustrates the elliptical shape of a geosynchronous transfer
orbit in green, and the circular shape of a geosynchronous orbit in blue. In a
first, SpaceX recently de-orbited a Falcon 9 upper stage from GTO after
deploying a communications satellite. Image credit: European Space
Agency
Over the course of the last few years, you've probably noticed a bit of an emphasis on trying to keep Earth orbit cleaner and less cluttered. This is a topic I've devoted column space to over the years - another example. I guess it's attractive to the greenies.
The Greenies don't care about the orbital 'environment.' Given half a chance, they'd have us never launching a single rocket again.
ReplyDeleteBut good for SpaceX. Being able to return a 2nd stage to a deorbit pattern is the first step of guiding 2nd stages to a parking orbit and using them for reuse or recycle.
Once again SpaceX does the unexpected and makes it seem normal.
Unsurprisingly, it seems the ones most interested in de-orbiting the upper stages are a couple of companies that see ways to make money off the industry. The last two links in the piece talk about a company trying to become the business that does the de-orbiting and NASA trying to take charge.
DeleteBut yeah: Once again SpaceX does the unexpected and makes it seem normal.
Well, eventually it has to be done.
ReplyDeleteStandardizing some protocols for GEO - tug hardware attach points, battery & solar isolation, and remnant propellant safing protocols - would be a lot cheaper than mandating the inclusion of a de-orbit booster with each satellite.
Orbital debris pollution seems to be the sort of "tragedy of the commons" type of problem that my will economy professor used to talk about.
Its not the satellites that need to de-orbit, its the boosters. Satellites in GEO, for some time, have been deployed with the ability, and intent that after they have served their in-orbit lifetime, that they be raised out of GEO into a higher parking/graveyard orbit. If you were to include a deorbit booster with each GEO satellite, it would have to be of an equivalent thrust (and mass) as the booster that raised the satellite to GEO in the first place.
DeleteThere are issues with graveyard orbits. Since the boost happens at the end of service life, often the necessary systems for the boost have failed. And the usual minute delta-v difference from GEO to GYO means that a catastropic failure can send debris back into GEO. Space is big, but Murphy's grasp extends even that far.
DeleteAnd, really, it is just kicking the can down the road, it is still littering and still a danger to traffic.
I think that SpaceX may have a market for orbital space tugs. Hear me out. That 2nd stage is right there, right? And eventually Starship is going to come on line bigly, right? The two are not mutually incompatable.
DeleteA little hardware, a little software, an orbital refueling system and those lame-duck second stages could be turned into orbital tugs. Floating around, pushing and pulling, because not everything needs to be supersized Starship size.
It might be fun. Or not.
And this leads me to wondering what the brains at SpaceX are thinking about? Are they working on secret ways to make money and/or equipment with the second stages? Or are they just going to shut down all Falcon systems? Inquiring minds want to know.
Beans is a steely eyed missile man. Relaunch, reuse, recycle.
ReplyDeleteI'm all for minimizing leftover space junk, having worked for GEODSS for almost a year and physically tracking ALL the crap in orbit. The Chinese, unsurprisingly, are the worst offenders.
ReplyDeleteNow that's amazing.
ReplyDelete