Quote from: spacenut on 03/31/2015 04:58 pmHere it is from ULA. Now, I'm talking about equipment landers since they are not going to take back off. Also Mars is only 38% earths gravity. Equipment for ISRU is going to be sent first, probably in mass. Being able to access it without the height restrictions is going to be easier. http://www.ulalaunch.com/uploads/docs/Published_Papers/Exploration/LunarLanderConfigurationsIncorporatingAccessibility20067284.pdfWe are in the SpaceX section. We are talking about a Mars Lander, I assume from SpaceX. Those will positively go back to Earth for reuse, crewed or cargo. Maybe not the first few, because they bring the ISRU equipment that enables return. But every craft that lands later will go back. Except possibly when they do the first landing on different far away locations where they again have no ISRU working initially.
Here it is from ULA. Now, I'm talking about equipment landers since they are not going to take back off. Also Mars is only 38% earths gravity. Equipment for ISRU is going to be sent first, probably in mass. Being able to access it without the height restrictions is going to be easier. http://www.ulalaunch.com/uploads/docs/Published_Papers/Exploration/LunarLanderConfigurationsIncorporatingAccessibility20067284.pdf
MTC is for humans. My topic was a horizontal lander for equipment, non-humans, so as to be easier to access once they get off the MTC and go to work on the colony. I thought it was obvious that equipment for ISRU equipment would be landed first to make fuel, water, and oxygen for air to breath just to get started and to refuel to get back. Solar panels will have to be landed and opened. Granted a lot of the is can be done robotically, however, access and maintenance will have to be done by humans, and the lower the better for safety of suited up humans.
It is confirmed that the whole MCT will land and then take off again? Or is that just reasoned speculation?
I was under the impression that the MTC was for travel between earth and Mars in space.
Quote from: Lobo on 03/30/2015 10:38 pmQuote from: guckyfan on 03/30/2015 07:35 pmQuote from: llanitedave on 03/30/2015 07:27 pmDo they really need to land horizontally?No of course not. It is just one of these ideas that keep popping up because nobody stakes them through the heart once and for all.Like artificial gravity for Mars transfer. Or hydrogen upper stages for Falcon 9/FH.There are reasons for horizontal landers. The major one being it's far easier to get heavy cargo off loaded, and assuming the crew cabin is on top of a vertical lander, it's far easier and safer to get crew into and out of a horizontal lander without risk of a major injury or death due to a fall. If you want to get that 2000lb rover off the lander and onto the ground, it's easier if it's 5 ft above the ground rather than 30ft above the ground...even in 1/3 gravity.But there are advantages to vertical landers too.I think a small swing-out crane and tackle system would be simpler and lighter than the hardware needed for horizontal landing.
Quote from: guckyfan on 03/30/2015 07:35 pmQuote from: llanitedave on 03/30/2015 07:27 pmDo they really need to land horizontally?No of course not. It is just one of these ideas that keep popping up because nobody stakes them through the heart once and for all.Like artificial gravity for Mars transfer. Or hydrogen upper stages for Falcon 9/FH.There are reasons for horizontal landers. The major one being it's far easier to get heavy cargo off loaded, and assuming the crew cabin is on top of a vertical lander, it's far easier and safer to get crew into and out of a horizontal lander without risk of a major injury or death due to a fall. If you want to get that 2000lb rover off the lander and onto the ground, it's easier if it's 5 ft above the ground rather than 30ft above the ground...even in 1/3 gravity.But there are advantages to vertical landers too.
Quote from: llanitedave on 03/30/2015 07:27 pmDo they really need to land horizontally?No of course not. It is just one of these ideas that keep popping up because nobody stakes them through the heart once and for all.Like artificial gravity for Mars transfer. Or hydrogen upper stages for Falcon 9/FH.
Do they really need to land horizontally?
Quote from: llanitedave on 03/31/2015 10:03 amQuote from: Lobo on 03/30/2015 10:38 pmQuote from: guckyfan on 03/30/2015 07:35 pmQuote from: llanitedave on 03/30/2015 07:27 pmDo they really need to land horizontally?No of course not. It is just one of these ideas that keep popping up because nobody stakes them through the heart once and for all.Like artificial gravity for Mars transfer. Or hydrogen upper stages for Falcon 9/FH.There are reasons for horizontal landers. The major one being it's far easier to get heavy cargo off loaded, and assuming the crew cabin is on top of a vertical lander, it's far easier and safer to get crew into and out of a horizontal lander without risk of a major injury or death due to a fall. If you want to get that 2000lb rover off the lander and onto the ground, it's easier if it's 5 ft above the ground rather than 30ft above the ground...even in 1/3 gravity.But there are advantages to vertical landers too.I think a small swing-out crane and tackle system would be simpler and lighter than the hardware needed for horizontal landing.It what way is a crane and tackle simpler and lighter than a horizontal landing?
Quote from: llanitedave on 04/01/2015 03:13 pmIt what way is a crane and tackle simpler and lighter than a horizontal landing?Far less hardware, simpler maneuvering, easier turnaround in case of a planned return.[/size]
It what way is a crane and tackle simpler and lighter than a horizontal landing?
@llanitedaveI can't see any advantages to a horizontal lander either.I think of the weight of the rockets on the 1st stage F9R. Its center of gravity, with fuel expended, is all in the bottom. A vertical take off and landing rocket has one set of rockets, doesn't require wings (folding x-wing control surfaces aside) or a runway. Horizontal landers bring nothing to the party (the Mars party especially considering lack of infrastructure) that isn't offset by a vertical landing rockets advantages/efficiencies.
MCT will probably be 30 meters wide so it will not have to be horizontal. However, whatever they plan to send using Falcon heavy might be horizontal because of launch diameter restrictions.
Horizontal landers would not have the rocket engines on the bottom, or end. They are launched, fully fueled, or refuel at a fuel depot along the way. They either come from a mother ship or are launched independently. After coming through the atmosphere, they land horizontally. Tanks can be on either end with engines in the middle sideways. Mars atmosphere isn't too thick so just some type of heat shield, maybe an inflatable one would be all that would be necessary. Also, I'm talking about single purpose, one time only use for equipment or even supplies. Empty tanks close to the ground could also serve as a shelter, a fuel depot station, etc.
Vertical landing of the booster is one thing as all the weight is on the bottom. A Mars only lander could be another shape. An extremely tall lander on Mars, would be very hard to unload.
If all the transported weight is on the bottom and unloaded. Wouldn't the rocket be top heavy when taking off after refueling on Mars for transport back to earth?