Impaler for the shorter distances aero lift and braking will not make any significant difference and have much less impact than gravity losses. Once you go above 2km/s in launch speed then it is possible that you can either use one of or both lift and drag to somewhat reduce the amount landing ΔV required. But you will still need a significant proportion of your launch ΔV to land even at the antipode.
Quote from: nadreck on 01/23/2016 08:31 pmNadreck, an abort scenario has to be realistic. If the BFS is able to be used as its own abort vehicle, it needs to be able to land. That means at least some engines are functional. So anything over half orbital velocity and your mission profile would be abort-to-orbit, then land at the base in the normal way once your orbit aligns with the base again.During the first couple of minutes, you're close enough and slow enough to RTLS. After 5-6 minutes you default to abort-to-orbit. So there's a narrow window where you can't make orbit, but can land, but are too far from the base to RTLS. That's not going to be 10,000km.(If they crash, they die.)
With a light payload, decent lift and ballistic coefficient, You shouldn't need more than 1km/s to land from orbit. It takes 4.5km/s or less to get to low orbit. 7km/s would be enough delta-V to land anywhere on the planet, maybe except Olympus Mons.
According to my simulations even 500 m/s is sufficient for landing at low altitude
Quote from: stoker5432 on 01/23/2016 08:32 pmAre you assuming the crew would have enough supplies By definition, somewhere between 3 and 9 months worth.
Are you assuming the crew would have enough supplies
Quote from: Robotbeat on 01/23/2016 09:31 pm According to my simulations even 500 m/s is sufficient for landing at low altitude can you give me your assumptions for this: altitude where you start calculating drag and lift, angle of flight at that altitude, velocity at that altitude, cross section area, mass
No threshold, I use an exponential atmosphere model. I posted a link above. It contains all assumptions.
I should point out that their are MANY possible reason why we might wish to abort to surface other then loss of engines, anything which endangers the long term life-support capability, or compromises the heat-shield which would make Earth entry in that vehicle dangerous. So I can't agree that any abort to surface is necessarily coming down with no propulsion and must therefore be a bailout.
Quote from: Impaler on 01/24/2016 06:55 amI should point out that their are MANY possible reason why we might wish to abort to surface other then loss of engines, anything which endangers the long term life-support capability, or compromises the heat-shield which would make Earth entry in that vehicle dangerous. So I can't agree that any abort to surface is necessarily coming down with no propulsion and must therefore be a bailout.Abort to orbit in most of those situations would be much safer since you're not risking landing in a compromised vehicle. The only reason you'd want to be on the surface rather than in orbit is if you literally can't get to orbit.
Quote from: Robotbeat on 01/24/2016 02:40 pmQuote from: Impaler on 01/24/2016 06:55 amI should point out that their are MANY possible reason why we might wish to abort to surface other then loss of engines, anything which endangers the long term life-support capability, or compromises the heat-shield which would make Earth entry in that vehicle dangerous. So I can't agree that any abort to surface is necessarily coming down with no propulsion and must therefore be a bailout.Abort to orbit in most of those situations would be much safer since you're not risking landing in a compromised vehicle. The only reason you'd want to be on the surface rather than in orbit is if you literally can't get to orbit.It depends on how the vehicle is compromised, if were in doubt of the vehicles thermal protection then aborting the launch immediately and landing propulsivly puts the vehicle through the least thermal load, less even then reaching orbit and then landing again.
Hi everyone, I just made a design concept, I'm a product designer, not engineer.Newest version: http://imgur.com/a/15fO2Initial concepts and idea development: http://imgur.com/a/EtH8F
Why are all the rocket tall and cylindrical? What are the disadvantages of launching disc like space ships?Is it possible to build a single stage spaceship that is capable of launching from earth and landing on mars?