Civilian job 401k and deployments

I am currently employed at a financial institution on the civilian side and will be going overseas in a few months for a deployment. I understand that the TSP is an option available to me in order to continue to put money into my retirement fund while I am overseas, but my civilian 401k through my civilian career (where I will be still employed, but absent) proves to be a better vehicle for investment.

I am aware that I can deposit into the TSP and then transfer the money over to my 401k upon my return. I also am aware that I can save with a Roth IRA (which I am and will be doing).

Update and learning points for all:

You can make a rollover from your TSP as stated here:
"Is the TSP authorized to make transfers to eligible retirement plans?
Yes. Participants may transfer eligible rollover distributions from their TSP accounts to a qualified trust or an
eligible retirement plan (as defined in IRC §402(c)(8)). See 5 USC § 8433(c)(2). An eligible retirement plan can be either an IRA or an eligible employer plan."

402c8:
Definitions. For purposes of this subsection
(A)
Qualified trust. The term "qualified trust" means an employees' trust described in section 401(a) which
is exempt from tax under section 501(a).
(B)
Eligible retirement plan. The term "eligible retirement plan" means—
(i)
an individual retirement account described in section 408(a),
(ii)
an individual retirement annuity described in section 408(b) (other than an endowment contract),
(iii)a qualified trust,
(iv)
an annuity plan described in section 403(a),
(v)
an eligible deferred compensation plan described in section 457(b) which is maintained by an eligible employer described in section 457(e)(1)(A), and
(vi)
an annuity contract described in section 403(b).
If any portion of an eligible rollover distribution is attributable to payments or distributions from a designated Roth account (as defined in section 402A), an eligible retirement plan with respect to such portion shall include only another designated Roth account and a Roth IRA.

This seems to be the only option in this realm for any reserve individuals who have an established program they wish to stay with. Deposit to the TSP and then make a rollover. I am currently attempting to find out how often you can make rollovers.