Unless by then they already have plenty of experience in fully powered landing I expect them to do parachute landing with propulsive assist. Which will have limited precision so they need something like Edwards Airforce base?
Parachutes with propulsive assist, Soyuz style but much softer, makes sense, but is even Edwards big enough given the dispersion from the lunar return trajectory?
Do they even need the main chutes? Could this be done with just the drogue chutes?
CST-100 will do that, in Edwards or elsewhere. I am sure Dragon can match their landing precision.
I think they will use the main chutes. They ensure safe, if harsh, landing even when the SuperDraco fail.
CST will do that from LEO. SpaceX demonstrated better than 1 km accuracy on their first return from LEO. Returning from the Moon is another thing all together.
CST will do that from LEO. SpaceX demonstrated better than 1 km accuracy on their first return from LEO. Returning from the Moon is another thing all together.
Yes, they have more time to do precision insertion into their landing corridor. That should get the targeting precision up.
While landing with drogues only may be feasible, I just don't see the advantage over full parachute landing. The option may be an additional failsafe, when the main chutes fail.
Landing with a drogue doesn't make sense to me. The landing is not survivable without the retro rockets firing. If you have to use the retro rockets just do a propulsive landing the drogues add nothing.
Landing with a drogue doesn't make sense to me. The landing is not survivable without the retro rockets firing. If you have to use the retro rockets just do a propulsive landing the drogues add nothing.Not quite true. Drogues would reduce terminal velocity a bit, therefore requiring less propellant for the landing itself.
That said, until they prove (really prove) the SuperDraco propulsive landing with the Cargo Dragons, I don't see them stopping the use of full parachutes. They may move to land landings, though. At least there is the Russian precedent for that. And Dragon landings would probably be a good deal softer.
If NASA can convince itself that it's safe to fly people on the first flight of STS and the second flight of SLS, why is it hard to believe SpaceX could convince itself it's safe to fly people on the second flight of Falcon Heavy? Falcon 9 flights might not retire all the risk of Falcon Heavy, but surely they retire a lot more of it than was retired before the first flight of STS and will be retired before the second flight of SLS.
Landing with a drogue doesn't make sense to me. The landing is not survivable without the retro rockets firing. If you have to use the retro rockets just do a propulsive landing the drogues add nothing.Not quite true. Drogues would reduce terminal velocity a bit, therefore requiring less propellant for the landing itself.
That said, until they prove (really prove) the SuperDraco propulsive landing with the Cargo Dragons, I don't see them stopping the use of full parachutes. They may move to land landings, though. At least there is the Russian precedent for that. And Dragon landings would probably be a good deal softer.
What is the expected mass difference with a cargo dragon vs a Dragon 2? Aren't they different in body, capability and mass?
http://www.space.com/36884-spacex-moon-mission-russia-rsc-energia.html
http://www.energia.ru/en/news/news-2017/news_05-02_1.htmlQuote from: Douglas MessierThe head of Russia's most prominent spaceflight company questioned whether Elon Musk's SpaceX will be able to launch people around the moon next year.<snip>
"As for the state of affairs specifically at Elon Musk's company, it would be difficult to carry out such a mission in 2018, and even in 2020," Vladimir Solntsev, general director of RSC Energia <snip>
"Nobody has yet even seen the designs. There’s no launch vehicle, no spacecraft," Solntsev added. "The Crew Dragon spacecraft designed for missions to the ISS and Falcon 9 launch vehicle are a far cry from a spacecraft and a rocket that are needed for a mission towards the moon."
Dragon 2 can probably land with the full payload (because it needs to do that in aborts), as far as I can tell Dragon has so far not landed with a full payload, it is unclear if that is because it can't or because there is less pressurized cargo to be returned.
http://www.space.com/36884-spacex-moon-mission-russia-rsc-energia.html
http://www.energia.ru/en/news/news-2017/news_05-02_1.htmlQuote from: Douglas MessierThe head of Russia's most prominent spaceflight company questioned whether Elon Musk's SpaceX will be able to launch people around the moon next year.<snip>
"As for the state of affairs specifically at Elon Musk's company, it would be difficult to carry out such a mission in 2018, and even in 2020," Vladimir Solntsev, general director of RSC Energia <snip>
"Nobody has yet even seen the designs. There’s no launch vehicle, no spacecraft," Solntsev added. "The Crew Dragon spacecraft designed for missions to the ISS and Falcon 9 launch vehicle are a far cry from a spacecraft and a rocket that are needed for a mission towards the moon."
Looks like mr. Solntsev is completely out of touch with reality. The rocket (FH) is built and being tested as we speak. The spacecraft is being built and tested as we speak, with first flight scheduled in 2018. Mr. Solntsev appears fully unaware that SpaceX designed crew Dragon to be much more capable than "just" a LEO spacecraft. Heatshield, ECLSS, Thermal Control systems, Longevity, Crew Systems, etc. are all designed for much more demanding missions than "just" flying to the ISS. As EM indicated only a few systems need modding for the circumlunar mission. Most notably the comms system to be deep-space comms enabled.
Mr. Solntsev also forgets that a LEO spacecraft (Soyuz) was modified by the Soviet Union into a craft (Zond) for unmanned circumlunar missions, with the intent of using that same design for eventual manned circumlunar missions. Exactly the same thing that SpaceX is doing for their circumlunar mission.
Note: the linked article on space.com was written by someone who was banned from this forum for "having an agenda" with regards to SpaceX.
http://www.space.com/36884-spacex-moon-mission-russia-rsc-energia.html
http://www.energia.ru/en/news/news-2017/news_05-02_1.htmlQuote from: Douglas MessierThe head of Russia's most prominent spaceflight company questioned whether Elon Musk's SpaceX will be able to launch people around the moon next year.<snip>
"As for the state of affairs specifically at Elon Musk's company, it would be difficult to carry out such a mission in 2018, and even in 2020," Vladimir Solntsev, general director of RSC Energia <snip>
"Nobody has yet even seen the designs. There’s no launch vehicle, no spacecraft," Solntsev added. "The Crew Dragon spacecraft designed for missions to the ISS and Falcon 9 launch vehicle are a far cry from a spacecraft and a rocket that are needed for a mission towards the moon."
Looks like mr. Solntsev is completely out of touch with reality. The rocket (FH) is built and being tested as we speak. The spacecraft is being built and tested as we speak, with first flight scheduled in 2018. Mr. Solntsev appears fully unaware that SpaceX designed crew Dragon to be much more capable than "just" a LEO spacecraft.
From the new GAO report http://www.gao.gov/assets/690/684626.pdf we learn that SpaceX plans to certify the commercial crew vehicles in Q3/2018 (see page 47). This is awfully close to the proposed date for the Grey/Silver Dragon mission.
Is CCP certification on the critical path for Grey Dragon? Could SpaceX launch Grey Dragon before CCP certification?
From the new GAO report http://www.gao.gov/assets/690/684626.pdf we learn that SpaceX plans to certify the commercial crew vehicles in Q3/2018 (see page 47). This is awfully close to the proposed date for the Grey/Silver Dragon mission.
Is CCP certification on the critical path for Grey Dragon? Could SpaceX launch Grey Dragon before CCP certification?
There is no hard window here, so it is virtually certain they will slide the mission to the right until the required boxes are checked off (crewed flight, certification, confidence in FH as a launcher).
There is no hard window here, so it is virtually certain they will slide the mission to the right until the required boxes are checked off (crewed flight, certification, confidence in FH as a launcher).
There is no hard window here, so it is virtually certain they will slide the mission to the right until the required boxes are checked off (crewed flight, certification, confidence in FH as a launcher).
It's pretty hard to use "there is no hard window here" and "they will slide the mission to the right" in the same sentence. Aren't the 2 statements mutually exclusive?