ISRO's Reusable Launch Vehicles

sasum

Atheist but not Communists.
Senior Member
Joined
Jan 14, 2016
Messages
1,435
Likes
761
There would be NO PARACHUTE. The vehicle would have made manoeuvres to landed perfectly horizontal on the water surface.
I expected this arguement !!!!
Naval aircrafts land on deck horizontally with parachute leashing it from behind. The parachute is deployed just before touch down when no other maneuver is required/ desired except deceleration. A winged RLV can be made to do the same.
 

Screambowl

Ghanta Senior Member?
Senior Member
Joined
Jan 1, 2015
Messages
7,950
Likes
7,908
Country flag
I expected this arguement !!!!
Naval aircrafts land on deck horizontally with parachute leashing it from behind. The parachute is deployed just before touch down when no other maneuver is required/ desired except deceleration. A winged RLV can be made to do the same.

there WILL be PARACHUTE WHEN it LANDS on THE STRIP. But THIS TeST was Without Parachute.

Splash on water and disintegrate. This was the plan. As no Undercarriage was installed.
 

abingdonboy

Senior Member
Joined
Sep 13, 2010
Messages
8,044
Likes
33,602
Country flag
I expected this arguement !!!!
Naval aircrafts land on deck horizontally with parachute leashing it from behind. The parachute is deployed just before touch down when no other maneuver is required/ desired except deceleration. A winged RLV can be made to do the same.
Which naval aircraft makes use of a parachute on landing? On carriers, aircraft (with the exception of V/STOL fighters) are "recovered" to the deck with the use of arrestor wires that are "hooked" by tail hooks on the aircraft.

In the case of the RLV in this test it was ALWAYS intended to disintergrate in the Bay of Bengal and never be recovered. After gliding back down it conducted a "simulated landing" on a simlulated runway in the middle of the water. The full size version will be landing (with undercarriage) on a yet to be made 5KM runway in Southern India so as to be fully re-useable. The purpose of this test was to validate the design and control functions of the vehicle which seem to have performed optimally so it was a full success.
 

abingdonboy

Senior Member
Joined
Sep 13, 2010
Messages
8,044
Likes
33,602
Country flag
K. Sivan, a scientist involved in the latest project, said the seven-metre (23-foot) long shuttle survived the test flight, and scientists hope subsequent models six times as big, to be built over the next decade, will glide safely back to land.

"We have located the place where the vehicle is floating. The landing was soft and the vehicle did not break," Sivan told AFP.
 

pmaitra

Senior Member
Joined
Mar 10, 2009
Messages
33,262
Likes
19,594
I checked quite a lot of news sites. Only two of them had the correct picture of the RLV-TD. Rest of them all had old pictures of PSLV and GSLV launches. Sorry if a repost. I haven't had time to check all the posts.


RLV-TD from The Hindu


RLV-TD from BBC
 

sasum

Atheist but not Communists.
Senior Member
Joined
Jan 14, 2016
Messages
1,435
Likes
761
@abingdonboy . I have not denied the arrestor wire routine. But Parachute assisted deceleration is also resorted to when pilot fails to slow down by deploying airbrakes. Here is a pic of Tejas landing with parachute-assistance.
Tejas2.jpg
 

abingdonboy

Senior Member
Joined
Sep 13, 2010
Messages
8,044
Likes
33,602
Country flag
@abingdonboy . I have not denied the arrestor wire routine. But Parachute assisted deceleration is also resorted to when pilot fails to slow down by deploying airbrakes. Here is a pic of Tejas landing with parachute-assistance.
View attachment 8717
No, I understand where you are coming from brother and I'm not denying that parachute assisted landings are commonplace for fighters landing on shore but for carrier fighters it is VERY different. The limited deckspace/landing area mean that parachutes are NEVER used as they don't offer the requisite speed break, this is why the tail hook/arrested landings take place. HOWEVER, where this is not possible (fault with the hook/undercarriage failure) the carrier crews utilise barrier/barricades in emergencies:










This is even fitted at some shore air bases- the iAF has a number of airbases with such systems in place for example.
 

sasum

Atheist but not Communists.
Senior Member
Joined
Jan 14, 2016
Messages
1,435
Likes
761
No, I understand where you are coming from brother and I'm not denying that parachute assisted landings are commonplace for fighters landing on shore but for carrier fighters it is VERY different. The limited deckspace/landing area mean that parachutes are NEVER used as they don't offer the requisite speed break, this is why the tail hook/arrested landings take place. HOWEVER, where this is not possible (fault with the hook/undercarriage failure) the carrier crews utilise barrier/barricades in emergencies:










This is even fitted at some shore air bases- the iAF has a number of airbases with such systems in place for example.
Tailhook landing is the norm on carriers when airbrakes have already managed to slow down the Jet. However, when pilots have to land 'with the wind' (wind behind them) airbrakes don't reduce speed sufficiently. In that case pilot deploys parachute to induce drag. You can watch clips of such landings on deck on youtube. I can't give links readily.
 

pmaitra

Senior Member
Joined
Mar 10, 2009
Messages
33,262
Likes
19,594
Regarding decelerating after landing, I would go with the preferred approach, i.e. to use parachutes.


Using arrestor wire risks damaging the heat shield tiles that are not only applied to the bottom, but also to the edges and the nose.
 

pmaitra

Senior Member
Joined
Mar 10, 2009
Messages
33,262
Likes
19,594
Its some what secret.......

Btw always found something similar here
What's will all the secrecy ??

Its not like that we are testing a nuke delivery system which can change directions and glide to a target at high speed and linked to MIRV developments .

Its not like we are testing something new and advanced and don't want copy and paste from others.

Its not like we did something new and challenging that is good.

Oh wait !!
I think ISRO is not considering this as a Space Shuttle mission. Rather, this is a stepping stone towards the Space Shuttle mission. This launch was a technology demonstrator (which is why they are not calling it RLV, but RLV-TD), and there will be few more I think.
 

Prashant12

Senior Member
Joined
Aug 9, 2014
Messages
3,027
Likes
15,002
Country flag
Runway for space shuttle coming up at Sriharikota


The project report, readied a couple of years back, is likely to be fast-tracked following the success of the first Hypersonic Experiment of RLV. | (File Photo | PTI

CHENNAI: A 5-km runway is coming-up at the nation’s spaceport, Sriharikota, to facilitate the landing of Reusable Launch Vehicle (RLV), which is under development.

The project report, which has been readied a couple of years back, is likely to be fast-tracked following the success of the first Hypersonic Experiment of RLV on Monday.

ISRO sources told Express that a site has already been identified near the Augumented Satellite Launch Vehilce (ASLV) complex. ASLV is now non-operational.

After the Hypersonic Experiment, there would be landing experiment (LEX), return flight experiment (REX) and scramjet propulsion experiment (SPEX).

To carry out the further experiments in the category, ISRO needs a runway to retrieve and reuse the vehicle, the sources said.

When asked, K Sivan, director, Vikram Sarabhai Space Centre (VSSC), said the proposal was already there and a final approval has to be obtained before the work commences.

http://www.newindianexpress.com/cit...-at-Sriharikota/2016/05/24/article3448064.ece
 
Last edited:

abingdonboy

Senior Member
Joined
Sep 13, 2010
Messages
8,044
Likes
33,602
Country flag
Tailhook landing is the norm on carriers when airbrakes have already managed to slow down the Jet. However, when pilots have to land 'with the wind' (wind behind them) airbrakes don't reduce speed sufficiently. In that case pilot deploys parachute to induce drag. You can watch clips of such landings on deck on youtube. I can't give links readily.
I am yet to see a single instance of a parahute being deployed where an arrestor landing takes place. There is simply no need for an extra deceleration device when you have an arrestor wire- the force it exerts is immense and it is able to halt even a large C-2 in a matter of 100m. Where is the need for a parachute on a carrier a/c? I just don't see it. And as I have said, where the tail hook/arrestor wire fails the last ditch option is for the "barrier" landing. Parachutes just don't provide sufficent deceleration on the limited deck of a carrier.


Regarding decelerating after landing, I would go with the preferred approach, i.e. to use parachutes.


Using arrestor wire risks damaging the heat shield tiles that are not only applied to the bottom, but also to the edges and the nose.
Of course for a shuttle/RLV using a parachute for deceleration is the optimal solution. I am simply refering to carrier fighters specifically and addressing the point about parachutes being used for tail hook landings- which they simply aren't.
 

Latest Replies

Global Defence

New threads

Articles

Top