Chinese Hypersonic Developments (HGVs/HCMs)

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nativechicken

Junior Member
Registered Member
ougoah said:
Even at an average speed of Mach 10 which is low for a skip glide vehicle spending lots of time near the Karman line, that is roughly 12,350km/hr average speed. Given a general straight line circumference of the Earth is approx 41,275 adjusted for a duration of flight at >99km altitude, a six hour flight is already more than one shortest distance circumnavigation of earth.

In reality, such a vehicle, like the hypersonic vehicle test flown in 21/22, the average speed would be well above mach 10. This would suggest at least a 2x circumnavigation "range".

Lets keep in mind this is a public university project. Affiliated with defence or not, PLA's own HGVs are leagues above this and only mentioned by US intelligence until their replacements are ready. At this point, China is clowning the US at hypersonics including powered hypersonic flight. India is still boasting about achieving scramjet combustion.
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It has been clarified that the maximum speed of the RBCC engine of Feitian-2 is Mach 6.
Actually, it's a good thing. Pneumatic heating becomes more severe at higher speeds.
Nowadays, in materials science, it is difficult to persist for longer under high temperature conditions.
1800s is the limit, this aircraft needs to fly for more than 21800 seconds.

Mach 6 can actually be controlled between 500-800 degrees at near space altitude (due to thin atmospheric density). If it is 8 Mach, this temperature range is the actual control temperature of 900-1200 degrees. The higher the speed, the higher the average temperature.
 
O

ougoah

Brigadier
Registered Member
nativechicken said:
It has been clarified that the maximum speed of the RBCC engine of Feitian-2 is Mach 6.
Actually, it's a good thing. Pneumatic heating becomes more severe at higher speeds.
Nowadays, in materials science, it is difficult to persist for longer under high temperature conditions.
1800s is the limit, this aircraft needs to fly for more than 21800 seconds.

Mach 6 can actually be controlled between 500-800 degrees at near space altitude (due to thin atmospheric density). If it is 8 Mach, this temperature range is the actual control temperature of 900-1200 degrees. The higher the speed, the higher the average temperature.
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Thanks for providing that detail. I was thinking the the rocket cycle's purpose would be to also accelerate the vehicle when > 90km above sea level hence accelerating it beyond the operating limits of the other cycles since it's basically not doing any air breathing at that altitude.

Speaking of propulsion, at this point it looks like it's a race between rotating detonation, oblique detonation and RBCC for China's "hypersonic cruise missiles". Between TBCC and TRCC for China's hypersonic SSTO/TSTO aircraft-spacecraft. All of these engines have been flown now in the past decade according to official sources. I've saved some of those but it would be good if this forum had a simple and effective bookmarking system to track all the major leaks/statements and evidence over the years.
 
T

taxiya

Brigadier
Registered Member
nativechicken said:
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The information revealed in the video shocked me!!!

  1. The vehicle operates at altitudes between 30–100 km (details below)!!!
  2. Its endurance exceeds 6 hours!!!
  3. The video's conclusion suggests that the uploader personally witnessed the first test flight of a new spacecraft. With declassification now possible, a major milestone for this mysterious new vehicle (distinct from the Feitian No.2 spaceplane) is expected later this year.
After discussing this in an aerospace group (filled with professionals), the potential details I heard are astounding!
This vehicle is designed as an air-breathing skip-glide vehicle with intermittent multi-cycle ignition:

  • At 30 km altitude, it ignites air-breathing engines to accelerate, then shuts down.
  • It enters a skip-glide trajectory, reaching an apogee of 100 km before descending.
  • Upon dropping back to 30 km, it reignites engines to repeat the energy-replenishing glide cycle.
This process enables 6-hour endurance – such extreme duration implies a near-space, air-breathing hypersonic vehicle with global-range capability potentially exceeding one full Earth orbit.

Of course, full success has yet to be achieved...
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I would not take that video for granted. Lots of what was said by the poster is his personal thinking and can not be taken as fact.

He has a channel on Youtube and videos there are much better in quality. Here is the link to the same video
.

I have been following him since the begining of him posing on Youtube. The person is in general reliable in making judgement, but has made number of basic errors due to misinterpretation of the subject and source. For example, he claims 6 hours endurance, you believe that? 6 hours of fuel in the size of Feitian-2?. Note, the biggest part is the 1st stage booster which will be dropped, the sustaining flight is the wave raider. To sustain 6 hours flight inside atomasphere no matter how thin is physically impossible. If there was a word "6 hours" that he heard, he might had mixed it up with something else or in a different context.
 
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O

ougoah

Brigadier
Registered Member
taxiya said:
I would not take that video for granted. Lots of what was said by the poster is his personal thinking and can not be taken as fact.

He has a channel on Youtube and videos there are much better in quality. Here is the link to the same video
.

I have been following him since the begining of him posing on Youtube. The person is in general reliable in making judgement, but has made number of basic errors due to misinterpretation of the subject and source. For example, he claims 6 hours endurance, you believe that? 6 hours of fuel in the size of Feitian-2?. Note, the biggest part is the 1st stage booster which will be dropped, the sustaining flight is the wave raider. To sustain 6 hours flight inside atomasphere no matter how thin is physically impossible. If there was a word "6 hours" that he heard, he might had mixed it up with something else or in a different context.
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It would be spending a lot of time with engines off and skipping along near the Karman line. So it's explained that this experimental craft gets boosted to high altitude around Karman line, skip glides, uses potential energy to sustain speed as it reduces altitude, then engines kick in a more oxygen rich altitude, engine increases craft's speed and altitude, engines off as it reaches higher altitude to perform more skip gliding near Karman line. Repeated until fuel depletes.

The engines are not firing for 6 hours. This engine is a RBCC so rocket and scramjet in one engine.

Most HGV are sustained by glide and momentum. Still, 6 hours is extreme flight duration. That's basically circumnavigating the Earth at an average altitude of 50km about 2 times over even at Mach 6 or 7. The "FOB" only performed one circumnavigation at average speed of mach 20
 
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taxiya

Brigadier
Registered Member
ougoah said:
It would be spending a lot of time with engines off and skipping along near the Karman line. So it's explained that this experimental craft gets boosted to high altitude around Karman line, skip glides, uses potential energy to sustain speed as it reduces altitude, then engines kick in a more oxygen rich altitude, engine increases craft's speed and altitude, engines off as it reaches higher altitude to perform more skip gliding near Karman line. Repeated until fuel depletes.

The engines are not firing for 6 hours. This engine is a RBCC so rocket and scramjet in one engine.

Most HGV are sustained by glide and momentum. Still, 6 hours is extreme flight duration. That's basically circumnavigating the Earth at an average altitude of 50km about 2 times over even at Mach 6 or 7. The "FOB" only performed one circumnavigation at average speed of mach 20
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That is still a speculation even though a reasonable one which is not necessarily what the poster meant which itself is not necessarily rightly sourced. My point was and is that people should not make conclusions or speculations on top of speculations based on favorable reading and interpretation, or when re-posting must realize and clarify what is stated from a source and what is personal opinion. In this case, the "6 hours" is not from member of the test team of NWPU, the video poster did not say where and how he got the "6 hours".
 
N

nativechicken

Junior Member
Registered Member
ougoah said:
It would be spending a lot of time with engines off and skipping along near the Karman line. So it's explained that this experimental craft gets boosted to high altitude around Karman line, skip glides, uses potential energy to sustain speed as it reduces altitude, then engines kick in a more oxygen rich altitude, engine increases craft's speed and altitude, engines off as it reaches higher altitude to perform more skip gliding near Karman line. Repeated until fuel depletes.

The engines are not firing for 6 hours. This engine is a RBCC so rocket and scramjet in one engine.

Most HGV are sustained by glide and momentum. Still, 6 hours is extreme flight duration. That's basically circumnavigating the Earth at an average altitude of 50km about 2 times over even at Mach 6 or 7. The "FOB" only performed one circumnavigation at average speed of mach 20
Click to expand...
My private sources confirm the "6-hour" timeframe is indeed an official technical target from the experimental team—not an achieved capability. However, such details remain undisclosed.

In principle, an energy-replenishing boost-glide near-space vehicle does possess the technical feasibility to circumnavigate Earth once.
 
B

bebops

Junior Member
Registered Member
Technically if they can create a mini version of long March rocket and attach a hypersonic glider, they can get 1 full circumnavigation around the earth once.
 
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