BURAN Orbital

Spaceship Airframe

Creation

BURAN with a Crew on Board

Bachurin I.I.
The paper contains the memoirs of the deserved test pilot of the USSR I.I. Bachurin about flights on the BURAN Analogue-Plane and Flying Laboratories. These flights were conducted under the Horizontal Tests Program that was executed to improve the control system on stage of automatic landing. This program has ensured success of the first orbital flight of the BURAN Orbital Spaceship.

The reusable BURAN Orbiter having done on November 15, 1988 its first space flight, for the first time in the world has executed the descent and aircraft airfield landing in the automatic mode without crew on board. But before, on the analogue of the orbiter, which we named ‘Second’ there were made so many automatic landings how many it was required to make a conclusion about the capability of successful unmanned landing of the Orbiter itself. These landings were made by the test pilots.

However it is necessary to tell you everything in the order. At the end of the eightieth years, when BURAN was not created yet in metal, and the algorithms its automatic modes of the flight only were developed, the test pilots began flights in interests of its future. On the production fighters, bombers and transport planes hundreds flights on the trajectories of descent of the Orbiter were made. At the first stage it was necessary to understand how to result on the landing strip without use of the engines thrust the airplane with the aerodynamic characteristics close to the characteristics of BURAN.

The flights on the trajectories of descent were executed at the minimal for these modes information maintenance of the pilot, i.e. on nominal piloting and navigational information of production planes. The special navigational information began to be developed much later. And now on known altitude, speed, range up to the runway and direction on it the pilots resulted on the aerodrome the plane decreasing with the vertical velocity 50-60 meters per second not using the engines for refinement of calculation on landing. Transfer of the plane on a flat trajectory near the ground was executed and the landing to the runway implemented.

Researches on SU-7b, TU-22M3, MIG-25, MIG-31, TU-154 airplanes in the beginning were carried out with the purpose of selection of flight vehicles similar on the characteristics of descent to the created orbiter with small lift-to-drag ratio. The most acceptable for the further researches there were planes MIG-25 and MIG-31 and also TU-154 plane that finished as the first flying laboratory for fulfillment of the passes and landings with live in the flight thrust reverse of the engines. On these planes all area of possible reduction of the orbiter was carefully studied, the technique of pass and landing was developed, the selection of the descent trajectory shape near the ground with the profile of transition on the flat trajectory before the second equalization was updated. On materials of these flights there were updated the algorithms of automatic modes and systems of display of the flight-navigation information for flying laboratories.

At the same years there were formed piloting stands that rendered invaluable service to the pilots in preparation for the flights in atmosphere on the orbiter and the developers of the orbiter systems. On first piloting stands the pilots chose the characteristics of systems and controls of the future ship. As the control post of the ship the central handle with small loading was adopted. Later on the stands the system of information display and many questions of ergonomics were fulfilled. The training’ on improvement of the piloting technique of the analogue of the ship from take-off till landing were executed. For this purpose the stands were equipped with the system of visualization of the underlying surface with the image of the runway. On stands there were chosen and fulfilled all possible abnormal situations as they are named in a ‘space’ lexicon connected to failures of engineering and errors of the software or those not stipulated by the mission plan.

For the number of years on piloting stands the test pilots made tens thousand modes on research and improvement of the Orbiter’s flight. The ground equipment and more perfect planes - laboratories TU-154LL equipped with control systems of the Orbiter and display of the information for fulfillment of the flights on the trajectory of BURAN in the automatic mode has appeared lately. On them the correctness of engineering solutions was checked up and the improvement of onboard and ground means of maintenance of automatic landing was made at their interaction. At last, shortly before the space flight of the orbiter, the pilots began the flights on the twin of BURAN. It differed from the BURAN Orbiter first of all by the presence on it of turbojet engines for a taking - off and output to the initial point for realization of the segment of the trajectory of the future descent from space and making the landing in the automatic mode.

After the number of flights for definition of the flight characteristics of the ship at manual control the subsequent flights were executed for check of the automatic control on modes of descent and landing down to the stop on the landing strip. The flights differed from each other by initial conditions before the actuation of the automatic control and modes of the further check of the characteristics of stability, controllability and strength of the ship executed at the manual control up to the exit

to the point of gliding start.

To understand the process of direct preparation of the crew to each flight and process of its fulfillment better, I shall bring my notes, as the captain, about the fulfillment of one of the flights on ‘Second’ in October, 1987.

‘About forthcoming flight we were announced for a week. The development of the task we finished after the preliminary fly-around of its modes on the bench. Then we made plotting boards, distributed the duties in the crew, fulfilled interaction. On the piloting stand we executed some training strictly on the task with the improvement of all abnormal situations, received the offset. On the eve of the day of the flights we were present at the session of methodical council by the definition of the flight readiness of the ship, ground means and the crew. The reports of the chiefs and the experts were laconic. There is little questions. The ground complex and the ship are serviceable. The crew is ready to fulfillment of the forthcoming task in full volume. The chairman has updated:
- Is there a necessity to the commander to execute the flight on TU-154LL on the given task?
- Yes, there is.
- Is the plane ready?
- Yes, it is.
- The flight to execute after the session.

We executed the flight on the flying laboratory on the forthcoming task without any remarks, passed the training in the cabin of the ship and executed the training engine start-up.

We spend the night on the aerodrome in the rest room as the flight was nominated to the early morning. In the evening we didn't speak about the forthcoming flight; have had already good long talk for one week. In the morning we look out in the window - what about the conditions? They promised strengthening of the wind. A toilet, lunch, medical monitoring. We are waiting for the command on departure. Mentally again, now on - large, I scroll the forthcoming flight. I have not hooked anything yet but the working condition do not feel either. In some minutes there comes the bell:
- Everything is ready. The bus has left for you.
- I see, we shall be in time.

We put on and leave to the bus. I catch the sensation of habitual pleasant readiness to execute the flight. We passed by passing preparation for the flight ‘Second’ to the launching house. Inside everybody is busy. There isn’t any attributes of the vanity. We passed into one of the rooms. We are not bothered by anybody.

In fifteen minutes there came the command: ‘The crew is to take its workplaces’. We go to the gangway. The lonely operator conducts recording. In the vestibule of the covered gangway the experts help us to put on the personal parachute harness system. On our knees we scroll through the hatch of the ship into the cockpit, occupy our workplaces. The experts leave the cabin, close the hatch. The pair of escort airplanes and the video-shootings reported about their readiness. We can start. In interaction with the mechanic and point of Flight Experiment Control Post (FECP) we do preparation for the start, start and transfer of the systems of the ship in the working condition. The experts on FECP supervise the passage of the commands onboard the ship and at any moment are ready to help us. The escort airplanes and video-shootings are off. We disconnect the ground power sources and taxi out on the runway. On running the plane is well controlled, the braking is effective. I try to store the altitude up to the ground (unusually high).

On the band we warm up the engines. The escort airplanes and the shootings take the basis in air to take the place near us after take-off of the ship. On the command from the pilot of the escort airplane we inject engines into the ascent mode, we check the parameters of the engines and systems.

We begin taking - off. On taking - off the plane is steady, well-controlled. The nose-wheel lift-off on the given speed occurs practically without delay on deviation of the control handle. Separation. Smoothly I reduce the deviation of the handle, the plane saves the given angle of the set.
The report of the right pilot, Borodai Alexei:
- I retract the undercarriage.
- The temperature of the second and third engines smoothly approaches to limitation.
The commander:
- Slightly tidy up, do not exceed.
- Has tidied up, the temperature stands.
It is good, that the right pilot actively live in the control loop of the ship is in constant readiness to help the commander.
- Wheels up.
On the modes of take-off the characteristic of stability and controllability of the ship a little bit differ from the characteristics received on the stand. The plane ‘densely sits on the handle’.
- On the place, - the report of the pilot of tracking. I look around - there is not far from us the fighter and further TU-134 making video record.

I warn the pilot of tracking and carry out the number of standard maneuvers used in flight tests for definition of the characteristics. I check activity of the air brake.

The altitude is the given one. Turn for the exit to the initial point. The FECP navigation officer precisely gives our place. The initial point. I transit the engines on an idle. I activate the automatic control unit. ‘Second’ very willingly executes the maneuver on the exit on the planned trajectory of the descent. We control the mode of flight on the steep trajectory of descent, the activity of the systems and air brake. The speed is computational one. The plane quickly comes nearer to the ground. There is a flare initiation. ‘Second’ smoothly decreases speed decrease. The landing gear has left. My hand is near the control handle of the ship. It is nit true that in the automatic mode we fly idle. TU-154LL ‘would be spread out’ if not the interference in control of Schukin Alexander when in one of flights in the automatics the plane ‘dived’ at the very ground. Altitude is of 200, 100, 50 meters. The plane is on the flat glide path.
- Thirty, twenty meters, - helps the second.
- We leave, - I put off the automatic control unit and increase the thrust of the engines. The second pilot combined the air brake and disconnected the mode of landing. The repeated pass was in the same sequence: with the mode of the automatic control up to the full stop on the runway.
- Altitude ten, five, three, two, one meter. The contact, - reports the pilot of tracking.
- There is a drogue parachute, - the right pilot confirms.

The deviation from the center-line of the runway is no more than two meters. The run is steady. The fighter of tracking comes near us finishing its activity by a beautiful zoom.

Lowering of the nose wheel is smooth. The braking of the wheels is effective. The automatic reset of the parachute is on the given speed. ‘Second’ stops on the band. We taxi in for the parking and after cutoff the engines we leave our workplaces and descend on the gangway on the ground. The worker and engineers goes to the spaceship. With thanks I look on those who conducted all the night the multi-hour automated preparation of ‘Second’ to the flight and with external restraint I share the clear to the professionals happiness of the creative realization of each of them in the joint achievement.

Then came the analysis of the flight and our report on the task. The chief of the tests names the date of the next flight’.

And the following flight is like this. All anew, with some features but with the same carefulness and coordination, without any deviation from the program of preparation of the ship and the crew.

And on November 15, 1988 we see on the large screen in Mission Control Center (MCC) as our BURAN smoothly executes transition to the flat glide path and, reducing its vertical velocity, softly contacts the landing strip. The drogue parachute is let out and the orbiter stops on the center-line of the runway. The first orbital flight of the ship in the automatic mode unmanned on board is completed. Everything like ‘Second’ flights made before.

We congratulate each other, see the delight of the experts of Center of flight control and the visitors; we recollect those who can not have failed to divide with us the pleasure of success. The two from ‘Second’ test pilots (Levchenko Tolya and Schukin Sasha) died some months before this. But we know: their contribution to the development of aircraft and astronautics will remain in the memory of those who go by their way.

November, 1988