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World’s Smallest Ion Thruster
Busek’s BIT-1 RF ion thruster is an ultra-compact,
high-performance ion propulsion device designed
with nano-satellite users in mind. Weighing just 53
grams and having a size close to a U.S. quarter, the
BIT-1 thruster can produce 105 µN thrust and 2250
second Isp with just 10W of power. When higher
power is available, the thruster’s performance can
easily exceed 200 µN thrust and 3500 second Isp.
As with other Busek RF ion thrusters, BIT-1
employs
inductively-coupled
plasma
(ICP)
discharge to generate its ion source. The utilization
of RF discharge eliminates the need for internal hot
cathode and thus increases overall lifetime while
enabling extreme miniaturization. Thruster life is
dominated by grid erosion, which by simulation
exceeds 20,000 hours. BIT-1 by default is paired
with Busek’s subminiature hollow cathode BHC-50E
for ion beam neutralization.
In addition to its small size and low power, BIT-1 is
designed to be compatible with the solid-storable
propellant iodine. Such unique properties make the
BIT-1 system extremely favorable for nano-satellites
such as CubeSats, where volume and mass are
highly constrained. Miniaturized, microcontrollerbased Power Processing Unit (PPU) for BIT-1 also
exists in the CubeSat form factor. The PPU
contains an innovative RF generator/amplifier board
with integrated load power sensor and automatic
frequency matching. Based on a modified Class E
RF amplifier topology, the RF board has a proven
80% DC-to-RF power conversion efficiency for
BIT-1 operation.
Very precise thrust output is possible with this
technology, as well as multiple modes of operation,
ranging from higher to lower specific impulse.
BIT-1 RF Ion Thruster
BIT-1 Operating with Xenon at 14W
High-Efficiency RF
Generator/Amplifier Board in
the CubeSat Form Factor
w w w . b u s e k . c o m
Est. Thurst from Beam Current, µN
Envelope Drawing
240
220
200
180
160
140
120
100
80
60
40
20
0.06sccm
0.05sccm
0.04sccm
6
7
8
9
10
11
12
13
14
15
16
Total Thruster Power*
Ion Beam Current
Propellant Mass Flow
Thrust
Specific Impulse
Propellant Utilization
Energy Efficiency**
Grid Input Voltage
Thruster Mass***
10 W
1.5 mA
4.9 µg/sec Xe
105 µN
2250 sec
43%
28%
2 kV
53 g
5000
4500
4000
3500
3000
0.05sccm
2000
0.04sccm
1500
1000
500
0
7
8
9
10
11
12
13
14
15
16
Total Thruster Power (RF + DC), W
42%
38%
* Does not include PPU efficiency or neutralizer consumption
** Defined as Pgrids/(Pgrids + PRF)
*** A complete BIT-1 propulsion system will need to include neutralizer, PPU, feedsystem, and propellant tank
34%
30%
0.06sccm
26%
0.05sccm
22%
0.04sccm
18%
14%
10%
6
Performance Characteristics (Xe)
7
8
9
10
11
12
13
14
15
16
Total Thruster Power (RF + DC), W
16
100%
15
90%
14
80%
13
12
0.06sccm
11
0.05sccm
10
0.04sccm
9
8
Propellant Utilization
Total Thruster Power (RF + DC), W
0.06sccm
2500
6
Energy Efficiency
Nominal Specification
Est. Isp from Beam Current, sec
Total Thruster Power (RF + DC), W
70%
60%
0.06sccm
50%
0.05sccm
40%
0.04sccm
30%
20%
10%
7
0%
6
5
6
7
8
9
10
6
RF Load Power (Discharge Power), W
7
8
9
10
11
12
13
14
15
16
Total Thruster Power (RF + DC), W
Busek Co. Inc.
11 Tech Circle, Natick, MA 01760 | 508.655.5565 | [email protected]
Copyright 2014, Busek Co. Inc. All Rights Reserved.
70011950 Rev-