Space tourism. Not to orbit but to a better view.

[spacefire]

How about suborbital trips to about 1000km altitude as an intermediate step between hops to the edge of space and full-fledged orbital trips?<br />Delta V about 4500m/s<br />Time in 0G approx 15minutes.<br />A lot of the systems that later would be used for orbital craft can be tested in a more benign environment.<br />Plus....the view!<br />From 1000km out you will get a much better view of the Earth as a whole than from LEO. You will truly feel out in space! <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[henryhallam]

I think that would be a great idea. dV would be a little higher due to gravity and drag loss but still something achievable with e.g. a two-stage hybrid rocket. You also get to test somewhat tougher re-entry systems.

 

[tap_sa]

What kind of trajectory that would be, is there enough horisontal movement that it would allow intercontinental trip? That would be nice bonus to sell, "From NY to Tokyo in 20 minutes" <img src="/images/icons/wink.gif" /><br /><br />I guess straight up/down is out of the question, reentry would be too rough.

 

[henryhallam]

With 5km/s dV the best ballistic horizontal distance is a shade over 1300nm. Not quite NY to Tokyo though...<br />I'm not sure on whether a reentry from a 1000km vertical trajectory would be unreasonable, I think (unmanned) sounding rockets have done it. Of course humans would be trickier. It would certainly be a bit of a different problem to a conventional reentry, in terms of heat and g-loads versus time.<br />

 

[chris_in_space]

Just to clarify things what exactely do you understand by suborbital trip to 1000km altitude? You just want to shoot a rocket vertically until it gets out of fuel at around 1000 km and then let it fall down. Because if its that it's not a very good idea (reentry issues). If it's a suborbital flight describing a large/flat parabole with the peek altitude at 1000 km than I think it's not very clever to stop there and return back to earth since getting to real orbit once you're so high and fast would require a very samll amount of additional delatV.<br /><br />In my opinion once your're 1000km high it's that you go to orbit nothing else. Btw you know that the ISS is in orbit at about 300km... <br />

 

[n_kitson]

That'll be funny:<br /><br />1:00 = Travel time from Manhatten to JFK<br />0:45 = Check-in time<br />0:30 = Boarding time<br />0:15 = Taxi time<br /><br />Total pre-departure time = 2:30.<br />(and another 2:30 on the other end)<br /><br />So, all in all 5h of pre- and post-departure time. And only 20 min of flight time?

 

[spacester]

FWIW and IIRC 1000 km is about the limit before you get into the inner Van Allen belt, so that is a well chosen number. An excellent suggestion, but . . . <br /><br />The flight profile described is getting closer to a weapons system profile than up and down to the same spaceport, so I dunno if it would be allowed by the PTB. <div class="Discussion_UserSignature"> </div>

 

[chris_in_space]

"It would certainly be a bit of a different problem to a conventional reentry, in terms of heat and g-loads versus time."<br /><br />Vertical reentry after free fall from 1000km altitude would defintely be impossible without some active retrorockets system or something similar. If vertical reentry at something like 4000m/s the atmosphere alone is not enough to slow the vehicule enough so that parachutes can be opened.<br />

 

[radarredux]

> <i><font color="yellow">So, all in all 5h of pre- and post-departure time. And only 20 min of flight time?</font>/i><br /><br />Not too different from flying from Northern California to Southern California now <img src="/images/icons/smile.gif" />.</i>

 

[spacefire]

A lifting reentry would work though, with your craft maneuvering in a wide circle around the departure point. <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[holmec]

>In my opinion once your're 1000km high it's that you go to orbit nothing else. Btw you know that the ISS is in orbit at about 300km...<<br /><br />I disagree. You are forgetting you are talking about tourists. a suborbital flight with a longer time in space than 4 minutes I believe would have a market. It may have a bigger market than an orbital flight. Because of the time it takes to launch, orbit and find a place to land and hit that window. I think most people would want to get on with their lives and experiece space for a few hours. Also for orbit you would need a bigger ship for people to move around in, a bathroom, meals, drinks, stewardess. On a suborbital you can get by with a pilot whose a guide and a few barf bags. <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>

 

[holmec]

>Vertical reentry after free fall from 1000km altitude would defintely be impossible without some active retrorockets system or something similar.<<br /><br />apollo did it from the moon, and that was a quarter of a million miles. And they only had a heat sheild put together by a groups of middle aged women (I found that out from "From the Earth to the Moon" dvds.....really cool stuff) <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>

 

[spacefire]

<font color="yellow">In my opinion once your're 1000km high it's that you go to orbit nothing else. Btw you know that the ISS is in orbit at about 300km...</font><br /><br />as I said in the first post, the DeltaV I calculated is about 4500m/s which is significantly less than the 7.9km/s neede to achieve orbit. <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[tap_sa]

<font color="yellow">">Vertical reentry after free fall from 1000km altitude would defintely be impossible without some active retrorockets system or something similar.<<br /><br />apollo did it from the moon, and that was a quarter of a million miles. "</font><br /><br />Apollos didnt drop vertically straight down, like none of the orbital crafts do. IIRC Apollo reentry angle was ~6.5 degrees negative (below from the horizon). If something jumps to 1000km altitude it must have some horisontal velocity at the apogee so that it too hits atmosphere in shallow angle. Dropping straight down from 1000km would mean a brief moment of two-digit Gs. The capsule might survive it but passengers would turn into jello.

 

[spacefire]

I wonder if a design like the SS1, but beefed up, would work for such re-entry speeds. <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[vt_hokie]

I guess this is a question only an astronaut could answer, but I wonder how much better the view is from LEO than from, say, 40,000 ft on a commercial airliner, or 50,000 ft on a business jet, 60,000 ft on the Concorde, 80,000 ft on a Mig 25, etc.

 

[drwayne]

I didn't think the 25's ceiling was that high...<br /><br /><img src="/images/icons/wink.gif" /><br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[drwayne]

I thought those were zoom climbs - but I have been proven to be quite senile of late...<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[JonClarke]

The MiG-25 has an operational crusing altitude of about 80,000', depending on type . Specially modified versions have reached over 120,000'.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[drwayne]

I know it was built in part for dealing with aircraft like the Valkrie, so that should not surprise me.<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[vt_hokie]

The Mig 25 was also supposedly capable of Mach 3.2, but it couldn't sustain that speed very long, and I think Mach 2.5 was probably closer to the realistic operating limit.

 

[spacefire]

with some cash, you can fly to 'over 80,000ft) in a Mig 25 <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[drwayne]

In the last few years, I have an increased tendency to air sickness (and general senility) - so they probably don't want me to go with them...<br /><br /><img src="/images/icons/wink.gif" /><br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[vt_hokie]

<i>"with some cash, you can fly to 'over 80,000ft) in a Mig 25"</i><br /><br />Indeed, as long as you're no taller than 6'2" and weigh no more than 120 kg, I believe it is, I assume including flight gear.<br /><br />http://www.incredible-adventures.com/edgeofspace.html <br /><br />I would consider it if I had the cash to burn! <img src="/images/icons/smile.gif" />

 

[spacefire]

edge of space <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>