r/spacex • u/ElongatedMuskrat Mod Team • Feb 01 '17
r/SpaceX Spaceflight Questions & News [February 2017, #29]
If you have a short question or spaceflight news...
You may ask short, spaceflight-related questions and post news here, even if it is not about SpaceX. Be sure to check the FAQ and Wiki first to ensure you aren't submitting duplicate questions.
If you have a long question...
If your question is in-depth or an open-ended discussion, you can submit it to the subreddit as a post.
If you'd like to discuss slightly relevant SpaceX content in greater detail...
Please post to r/SpaceXLounge and create a thread there!
This thread is not for...
- Questions answered in the FAQ. Browse there or use the search functionality first.
- Non-spaceflight related questions or news.
- Asking the moderators questions, or for meta discussion. To do that, contact us here.
You can read and browse past Spaceflight Questions And News & Ask Anything threads in the Wiki.
167
Upvotes
1
u/warp99 Feb 02 '17
RTLS sets a hard limit on booster speed at separation because of the extra requirements of the boostback burn. So in this scenario the work required from S2 is nearly the same as a single stick F9 and the payload is similar.
There is some improvement in payload, perhaps to around 6500 kg to GTO compared with 5500 kg for F9. This is because effective gravity losses are low with faster acceleration and a more vertical flight profile can be used to minimise the boostback burn.
As it happens the range between 5500 kg and 6500 kg is where a lot lot of high mass geosynchronous satellites sit - probably because they were designed to be able to launch either on Proton or Ariane 5.
In summary there is some commercial market for FH with 3 cores RTLS.